The effects of infection by the human cytomegaloviruses Ad-169 on the incorporation of [14C]acetate into the polar and neutral lipids of human embryonic lung cells and human saphenous vein smooth muscle cells were compared to [14C]acetate incorporation in mock-infected control cells. Cytomegalovirus infection caused a shift in the relative amounts of polar and neutral lipids, with infected cells having lower amounts of polar lipids and higher amounts of neutral lipids than mock-infected controls. When neutral lipids were separated into diglyceride (DG), cholesterol (C), fatty acid, triglyceride (TG) and cholesterol ester (CE) components, Ad-169-infected cells had lower levels of incorporation of label into CE, TG, and DG fractions, and higher levels of label incorporation into C than mock-infected cells.