Levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c), as well as the TC:HDL-c ratio, were compared in patients receiving different antiretroviral therapy regimens. Patients receiving first-line regimens including protease inhibitors (PIs) had higher TC and TG levels and TC : HDL-c ratios than did antiretroviral-naive patients; patients receiving 2 PIs had higher levels of each lipid. Ritonavir-containing regimens were associated with higher TC and TG levels and TC : HDL-c ratios than were indinavir-containing regimens; however, receipt of nelfinavir was associated with reduced risk of lower HDL-c levels, and receipt of saquinavir was associated with lower TC : HDL-c ratios. Patients receiving nonnucleoside reverse-transcriptase inhibitors had higher levels of TC and LDL-c than did antiretroviral-naive patients, although the risk of having lower HDL-c levels was lower than that in patients receiving a single PI. Efavirenz was associated with higher levels of TC and TG than was nevirapine.