The objective of the study was to determine cumulative incidence and risk factors of nevirapine (NVP)-associated rashes that lead to NVP discontinuation among HIV-infected patients with CD4 <250 cells/microL. A retrospective cohort study was conducted among antiretroviral-naïve HIV-infected patients who had baseline CD4 <250 cells/microL and were initiated NVP-based antiretroviral therapy (ART) between January 2003 and October 2005. There were 910 patients with a mean age of 35.4 years and 43% were women. Median CD4 cell count was 27 cells/microL and median HIV RNA was 5.5 log copies/mL. Cumulative incidences of rashes at 0.5, 1, 2, 3 and 6 months after ART were 3.7%, 6.2%, 8.1%, 8.5% and 8.5%, respectively. By Kaplan-Meier analysis, the higher baseline CD4 cell counts had a higher probability of NVP-associated rashes (log-rank test, P=0.041). By Cox regression analysis, higher baseline CD4 cell count was associated with a higher incidence of rashes (hazard ratio=1.244, 95% confidence interval=1.045-1.482, for every 50 cells/microL increment of baseline CD4 stratum). In conclusion, NVP-associated skin rashes that lead to NVP discontinuation are common among HIV-infected patients with baseline CD4 <250 cells/microL. Despite the low baseline in this population, the higher number of baseline CD4 cells is continuously associated with a higher risk for skin rashes.