OBJECTIVES: To assess long-term changes in lipids and lipoproteins concentrations associated with exposure to non-nucleoside reverse transcriptase inhibitors. METHODS: Long-term analysis of plasma lipid concentrations was performed in patients starting first-line antiretroviral therapy with stavudine (d4T) and lamivudine, and either nevirapine or efavirenz. RESULTS: Concentrations of total cholesterol, low-density lipoprotein cholesterol and triglycerides continued to increase, while high-density lipoprotein cholesterol showed a slight decrease compared with earlier reported increases after 48 weeks. CONCLUSIONS: Changes in body fat distribution expected to occur with continued exposure to d4T could offer a potential explanation for these findings.