Interpretation of the experimental literature on epididymal glycerophosphorylcholine metabolism according to a recently proposed de novo pathway for the synthesis of acyl-specific phosphatidylcholine suggests that epididymal glycerophosphorylcholine is an intermediate of this proposed pathway. This glycerophosphodiester is postulated to be utilized by spermatozoa to synthesize docosahexaenoic phosphatidylcholine, proposed to be required for the development of sperm motility. A defect in glycerophosphorylcholine synthesis might be responsible for some forms of asthenozoospermia.