Complementary and alternative medical therapies (CAM) are popular with patients who are human immunodeficiency virus (HIV) seropositive, despite effective drug treatments, potential drug interactions, and overlapping toxicities. To determine rates and correlates of ingested and noningested CAM use, and to examine temporal changes in the rates of ingested CAM use during the introduction of highly active antiretroviral therapy (HAART). Cross-sectional analysis with repeated measures from a cohort study, with the study visit as the unit of analysis. Eastern Massachusetts and Rhode Island. Adults who are HIV seropositive followed semiannually (n = 642) in Nutrition for Healthy Living (NFHL) study. Rates of ingested and noningested CAM use were assessed by interview every 6 months between 1995 and 1999. Ingested CAM use was reported at 60% of visits. Between 1995 and 1999, HAART use increased from 0% to 70%, and ingested CAM use decreased from 71% to 52%. In multivariate analyses, users of ingested complementary therapies were more likely to be gay men (prevalence ratio [PR] 1.40, 95% confidence interval [CI] 1.23-1.58; p < 0.0001), at least high school educated (PR 1.37, 95% CI 1.12-1.68, p = 0.002), and with secure housing (PR 0.75, 95% CI 0.61-0.92; p = 0.007). Even in the lowest risk group (less educated, nongay males with insecure housing), CAM use rates were 27% (95% CI 21%-34%). There was no association between HAART and CAM use. CAM therapies complement, rather than replace, HAART. Even among poorly educated, nongay male patients with insecure housing, rates of ingested CAM use were substantial. Physicians should routinely ask about ingested CAM therapy use and become knowledgeable about potential hazards.