The purpose of this randomized, double-blind study was to test the safety and immunogenicity of an HIV-1LAI recombinant gp160 (rgp160) vaccine in healthy, uninfected volunteers using accelerated dosing schedules. Thirty volunteers were randomly assigned to receive 50-micrograms doses of rgp160 in one of two immunization schedules. Group 1 received rgp160 at times 0, 1, 2 and 5 months; and group 2 received rgp160 at times 0, 1, 2, 3 and 4 months. The vaccine was safe and stimulated high levels of HIV-1 envelope-specific binding antibody and T cell memory. There was a trend (P < 0.10) suggesting neutralizing antibodies were better induced by the regimen incorporating a rest period before the final immunization in group 1 volunteers. Both accelerated immunization schedules induced immune responses at levels similar to or better than those achieved by four rgp160 vaccine injections given over 12-18 months in other studies.