Although highly active antiretroviral therapy (HAART) has decreased the morbidity and mortality caused by HIV infection, its use has been associated with lipid abnormalities, particularly elevations in serum triglycerides. Hypertriglyceridemia is a risk factor in the development of cardiovascular and cerebrovascular disease as well as pancreatitis. Lipid-lowering drugs called fibrates have been part of the recommended treatment for elevated triglycerides, but the response to fibrates is incomplete in a large proportion of people. Fish oil capsules containing large amounts of omega-3 fatty acids have been shown to decrease serum triglycerides. However, fish oil supplements or fibrates alone are often inadequate for treating hypertriglyceridemia in people taking HAART. This study will determine whether the combination of the two therapies will lower serum triglycerides in people on HAART more effectively than either therapy alone.