| Cover Page | Nov. 10, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 10, 2020 |
| Entity Registrant Name | PULMONX CORPORATION |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39562 |
| Entity Tax Identification Number | 77-0424412 |
| Entity Address, Address Line One | 700 Chesapeake Drive |
| Entity Address, Postal Zip Code | 94063 |
| Entity Address, State or Province | CA |
| Entity Address, City or Town | Redwood City, |
| City Area Code | 650 |
| Local Phone Number | 364-0400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Trading Symbol | LUNG |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001127537 |
| Amendment Flag | false |
