To determine the incidence of clinically significant adverse events after long-term, fixed-dose, generic highly active antiretroviral therapy (HAART) use among HIV-infected individuals in South India, we examined the experiences of 3154 HIV-infected individuals who received a minimum of 3 months of generic HAART between February 1996 and December 2006 at a tertiary HIV care referral center in South India. The most common regimens were 3TC + d4T + nevirapine (NVP) (54.8%), zidovudine (AZT) + 3TC + NVP (14.5%), 3TC + d4T + efavirenz (EFV) (20.1%), and AZT + 3TC + EFV (5.4%). The most common adverse events and median CD4 at time of event were rash (15.2%; CD4, 285 cells/microL) and peripheral neuropathy (9.0% and 348 cells/microL). Clinically significant anemia (hemoglobin <7 g/dL) was observed in 5.4% of patients (CD4, 165 cells/microL) and hepatitis (clinical jaundice with alanine aminotransferase > 5 times upper limits of normal) in 3.5% of patients (CD4, 260 cells/microL). Women were significantly more likely to experience lactic acidosis, while men were significantly more likely to experience immune reconstitution syndrome (p < 0.05). Among the patients with 1 year of follow-up, NVP therapy was significantly associated with developing rash and d4T therapy with developing peripheral neuropathy (p < 0.05). Anemia and hepatitis often occur within 12 weeks of initiating generic HAART. Frequent and early monitoring for these toxicities is warranted in developing countries where generic HAART is increasingly available.