United States securities and exchange commission logo June 7, 2021 Teofilo Raad Chief Executive Officer and President Pulmatrix, Inc. 99 Hayden Avenue, Suite 390 Lexington, MA 02421 Re: Pulmatrix, Inc. Registration Statement on Form S-3 Filed May 26, 2021 File No. 333-256502 Dear Mr. Raad: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Please contact Tom Kluck at 202-551-3233 with any questions. Sincerely, Division of Corporation Finance Office of Life Sciences cc: Rick Werner