Mature male rats were given, orally, 14C-fructose either alone or in conjunction with dihydroxyacetone, glyceraldehyde, or glycerol. Glycerol was also administered with 14C-glucose in a dose equimolar with fructose. After 2 hr the rats were killed and the liver triglyceride fraction was separated. Estimations of the degree of incorporation of 14C from the radioactive labeled carbohydrate into the glycerol and fatty acid moieties were carried out. Dihydroxyacetone and glyceraldehyde reduced the incorporation of 14C-fructose into hepatic triglyceride to approximately equal extents, suggesting that both trioses contribute equally to alpha-glycerophosphate formation. Glycerol, however, brought about a profound increase in the amount of fructose converted to triglyceride. This effect of glycerol was not apparent to any measurable extent on glucose incorporation into triglyceride and none of the intermediates affected the proportional distribution of radioactive counts between the fatty acid and glycerol moieties of the triglyceride after 14C-fructose administration.