The present study examined effects of a 3-h stress management program for Japanese hospital staffs that included relaxation and assertion training. Twenty-seven hospital staffs (mean age: 29.4 yr) in a stress management group and 28 hospital staffs (mean age: 29.5 yr) in a wait-list group answered evaluation surveys at both pre- and post-intervention. Self-administered questionnaires including items on job stress, coping strategies, and interpersonal behaviors were evaluated. The stress management program was given six different participant groups: 3 groups were the stress management group and 3 groups were the wait-list group. The program increased active coping and decreased dependent behavior scores significantly in the stress management group, while decreasing assertive behavior scores in the wait-list group. A comparison of the education sub-groups showed that the first group had significantly increased assertiveness and decreased dependency scores. The second group had significantly decreased depression-anxiety scores. The data analyzed for men and women separately showed the stress management intervention significantly improved active coping and assertive behavior in men and dependent behavior in women. A brief one-time stress management program can be effective in improving active coping and assertive behaviors as well as reducing dependent behavior in hospital staffs. Sex differences were noteworthy.