| Cover - USD ($) | 12 Months Ended | ||
| Oct. 31, 2021 | Feb. 09, 2022 | Apr. 30, 2021 | |
| Cover [Abstract] | |||
| Entity Registrant Name | PHARMA-BIO SERV, INC. | ||
| Entity Central Index Key | 0001304161 | ||
| Document Type | 10-K/A | ||
| Amendment Flag | true | ||
| Entity Voluntary Filers | No | ||
| Current Fiscal Year End Date | --10-31 | ||
| Entity Well Known Seasoned Issuer | No | ||
| Entity Small Business | true | ||
| Entity Shell Company | false | ||
| Entity Emerging Growth Company | false | ||
| Entity Current Reporting Status | Yes | ||
| Document Period End Date | Oct. 31, 2021 | ||
| Entity Filer Category | Non-accelerated Filer | ||
| Document Fiscal Period Focus | FY | ||
| Document Fiscal Year Focus | 2022 | ||
| Entity Common Stock Shares Outstanding | 22,969,486 | ||
| Entity Public Float | $ 17,131,449 | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Entity File Number | 000-50956 | ||
| Entity Incorporation State Country Code | DE | ||
| Entity Tax Identification Number | 20-0653570 | ||
| Entity Address Address Line 1 | Pharma-Bio Serv Building, #6 Road 696 | ||
| Entity Address City Or Town | Dorado | ||
| Entity Address Country | PR | ||
| Entity Address Postal Zip Code | 00646 | ||
| City Area Code | 787 | ||
| Local Phone Number | 278-2709 | ||
| Entity Interactive Data Current | Yes | ||
| Amendment Description | This Annual Report on Form 10-K/A is being filed by Pharma-Bio Serv, Inc. (the “Company”) to amend the Annual Report on Form 10-K for the year ended October 31, 2021 filed by the Company with the Securities and Exchange Commission (the “SEC”) on February 11, 2022 to include the information required to be disclosed by Part III, Items 10-14 of Form 10-K. |
