Baseline cytomegalovirus (CMV) viremia among individuals with HIV starting ART was associated with advanced infection, but only persistent CMV viremia following ART initiation was associated with increased morbidity and mortality risk, according to results published in AIDS. Jean-Michel Molina, MD, PhD, and colleagues conducted a retrospective analysis of four clinical trials, using stored plasma samples to measure CMV viremia at baseline (before starting ART) and through 1 year after starting ART. The study included 3,176 participants (1,169 from FIRST, 137 from ANRS REFLATE TB, 54 from SMART, and 1,816 from START). Baseline CMV viremia prevalence rates were 17%, 26%, 0%, and 1%, respectively, and were associated with low CD4 T-cell counts and high HIV RNA levels when pooled across trials. In FIRST, CMV viremia was found in only 5% of participants between baseline and month 8. Following adjustment for CD4 T-cell count and HIV RNA levels, HRs for risk of clinical outcomes were 1.15 (0.86-1.54) and 2.58 (1.68-3.98) in FIRST participants with baseline and follow-up CMV viremia, respectively.