The metabolism of di[1-C-14]octanoylglycerol metabolism was examined in four cell lines: NIH 3T3 fibroblasts, BHK cells, Pam 212 keratinocytes and WEHI 3BD+ cells. We found the direct conversion of 1,2-di[1-C-14]octanoyl-sn-glycerol ([C-14]diC8) into dioctanoylphosphatidylcholine and dioctanoylacylglycerol, but no formation of phosphatidylinositol. The [C-14]diC, also underwent lipolytic breakdown. In contrast, 1-[1-C-14]oleoyl-2-acetyl-sn-glycerol was metabolized exclusively by lipolysis. Our findings support a new scheme for the metabolic termination of diacylglycerol signals.