October 24, 2018

Ben Silbert
General Counsel and Secretary
Avista Healthcare Public Acquisition Corp.
65 East 55th Street
18th Floor
New York, NY 10022

       Re: Avista Healthcare Public Acquisition Corp.
           Amendment No. 1 to Registration Statement on Form S-4
           Filed October 9, 2018
           File No. 333-227090

Dear Mr. Silbert:

      We have reviewed your amended registration statement and have the
following
comments. In some of our comments, we may ask you to provide us with
information so we
may better understand your disclosure.

       Please respond to this letter by amending your registration statement
and providing the
requested information. If you do not believe our comments apply to your facts
and
circumstances or do not believe an amendment is appropriate, please tell us why
in your
response.

       After reviewing any amendment to your registration statement and the
information you
provide in response to these comments, we may have additional comments. Unless
we note
otherwise, our references to prior comments are to comments in our September
27, 2018 letter.

Amendment No. 1 to Registration Statement on Form S-4 filed on October 9, 2018

Risk Factors, page 38

1.     Please include a separate risk factor clarifying the relationships
between the PIPE
       Investors, AHCAP, your sponsor and Avista Capital Partners. The risk
factor discussion
       should identify the members of the PIPE Investment Committee and any
other PIPE
       Investors who are affiliated with AHCAP, Avista Acquisition Corp, and
Avista Capital
       Holdings and identify any individuals who negotiated on behalf of both
AHCAP and the
       PIPE Investors in the merger and the PIPE Investors' investment.
 Ben Silbert
FirstName LastNameBen Acquisition Corp.
Avista Healthcare Public Silbert
Comapany NameAvista Healthcare Public Acquisition Corp.
October 24, 2018
October 24, 2018 Page 2
Page 2
FirstName LastName
2.       Please include a separate risk factor to clarify that the aggregate
investment of the PIPE
         Investors' per share investments in the post transaction company is at
a substantial
         discount to the public shareholders' investment. The risk factor
should clarify that the
         PIPE Investors' investment in the post combination shares is $5.91 per
share.
The Business Combination, page 103

3.       Please tell us how the overlapping merger, PIPE Investors'
subscription in AHCAP,
         Organogenesis private placement to the PIPE Investors and the
redemption of AHCAP
         public shares transaction involving AHPAC shares complied with
Regulation M's trading
         prohibitions.
4.       We note your disclosure on page 7 that AHPAC received the approval of
its shareholders
         to extend the deadline for AHPAC to complete a business combination to
February 15,
         2019. We note that Section 49.1 of AHPAC's amended and restated
memorandum and
         articles of association provides that Section 49.4 "may not be amended
prior to the
         consummation of a Business Combination without a Special Resolution,
the approval
         threshold for which is unanimity (100%) of all Members entitled to
vote." We understand
         that the holders of 84% of ordinary shares entitled to vote approved
your proposal to
         extend the deadline, which would appear to be short of the unanimous
vote required.
         Therefore, please tell us how the deadline to complete the business
combination was
         extended in accordance with AHPAC's articles of association and the
requirements of
         Schedule 14A.
5.       We note your disclosure on page 185 that in connection with the
extraordinary general
         meeting to extend the date by which AHPAC has to complete a business
combination,
         99% of AHPAC's Class A ordinary shares were redeemed. Please tell us
why your offer
         to redeem Class A ordinary shares was made without compliance with the
provisions of
         Exchange Act Rule 13e-4 and Regulation 14E. Alternatively, please tell
us why you
         believe such compliance is not required. Additionally, we note that
following the
         redemption of 99% of AHPAC Class A ordinary shares, an aggregate of
201,981 AHPAC
         Class A ordinary shares are outstanding. We further note that pursuant
to a subscription
         agreement, Avista Capital Partners Fund IV LP (an affiliate of the
AHPAC) purchased
         shares in AHPAC and also purchased approximately 3,200,000 shares of
merger target
         Organogenesis, which seems to place insiders of AHPAC on both sides of
the merger
         transaction. It appears that such redemption could be part of a
transaction or series of
         transactions which could have a reasonable likelihood of being
eligible to terminate your
         reporting status or in the de-listing of AHPAC ordinary shares. Please
provide us with
         your analysis as to the applicability of Exchange Act Rule 13e-3.
The AHPAC Board's Reasons for the Approval of the Business Combination, page
113

6.       We note your response to comment 17. Please revise your registration
statement to
         include the comparable company analysis. The disclosure should explain
how the
         comparable companies were selected, if any companies that met the
selection criteria were
 Ben Silbert
Avista Healthcare Public Acquisition Corp.
October 24, 2018
Page 3
      excluded from the analysis, the financial metrics used in the analysis,
and Organogenesis
      2019 estimated revenue and 2018 estimated gross margin percentages used
in the
      analysis. Additionally, explain how you estimated 2019 revenues and gross
margin for
      the comparable companies.
Certain Relationships and Transactions, page 281

7.    Please expand your disclosure to include the PIPE Investors transactions
with AHPAC
      and Organogenesis.
       You may contact Keira Nakada at 202-551-3659 or Kevin Vaughn at
202-551-3494 if
you have questions regarding comments on the financial statements and related
matters. Please
contact Christine Westbrook at 202-551-5019 or Suzanne Hayes at 202-551-3675
with any other
questions.



                                                           Sincerely,
FirstName LastNameBen Silbert
                                                      Division of Corporation
Finance
Comapany NameAvista Healthcare Public Acquisition Corp.
                                                      Office of Healthcare &
Insurance
October 24, 2018 Page 3
cc:       Jackie Cohen, Esq.
FirstName LastName