Prevention case management (PCM) for HIV-infected persons is an HIV risk reduction intervention designed to assist clients who are aware of their HIV infection and who continue to engage in risk transmission behaviors. PCM combines individual risk reduction counseling with case management to address the psychosocial factors affecting HIV transmission. More than 350 HIV-positive clients participated in PCM in Wisconsin between 2000 and 2003, and 109 completed both baseline and follow-up risk assessments. The percentage of clients reporting risk transmission behaviors, specifically unprotected vaginal intercourse, insertive anal intercourse, or needle sharing with partners of negative or unknown HIV status, declined from 41.3% at baseline to 29.4% at follow-up (p = 0.04). Furthermore, clients showed progression (p < or =.05) through stages of change using Prochaska and DiClemente's transtheoretical model on seven domains related to HIV transmission risk, including personalizing risk of HIV transmission and sexual risk behavior.