| Cover | Mar. 21, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 21, 2022 |
| Entity File Number | 001-36199 |
| Entity Registrant Name | PULMATRIX, INC. |
| Entity Central Index Key | 0001574235 |
| Entity Tax Identification Number | 46-1821392 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 99 Hayden Avenue |
| Entity Address, Address Line Two | Suite 390 |
| Entity Address, City or Town | Lexington |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02421 |
| City Area Code | (781) |
| Local Phone Number | 357-2333 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | PULM |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
