Most US jails and prisons do not provide condoms to prisoners because of concerns about possible negative consequences. Since 1989, the jail system of San Francisco, California, has provided condoms to male prisoners through 1-on-1 counseling sessions. Given the limitations of this approach, we installed, stocked, and monitored a free condom-dispensing machine in a jail to examine the feasibility of this method of providing condoms to jail prisoners. After the machine was installed, we observed increases in prisoners' awareness of programmatic access to condoms and in their likelihood of having obtained condoms. Particularly large increases in condom uptake were reported among those in high-risk groups. Sexual activity did not increase, custody operations were not impeded, and staff acceptance of condom access for prisoners increased.