Exposure to marijuana adversely affects spermatogenesis in humans and rodents. Since the Sertoli cell interfaces between changes in the serum hormonal milieu and the adluminal compartment and acts in various ways to support the germinal epithelium, this adverse marijuana mediated effect might be transmitted locally in the testes of humans by interference with Sertoli cell function. This report describes the effect of three active marijuana components: delta-9-tetrahydrocannabinol (THC), cannabidiol (CD) and cannabinol (CN) on various human Sertoli cell markers: transferrin, protein secretion and gamma glutamyl transpeptidase activity utilizing cultured human Sertoli cells. THC, CD, and CN tested in concentrations up to 200 ng/ml did not change transferrin secretion by these human Sertoli cells. Transferrin represents 1-4% of the total newly synthesized proteins of human Sertoli cells in culture. Even when the Sertoli cells were incubated for 30 days with THC there was no effect on transferrin secretion. The presence or absence of follicle-stimulating hormone, testosterone (T) or Fe3+ in the culture media did not modify the effect of THC. THC, CD, and CN also did not alter total protein secretion by Sertoli cells nor affect the level of gamma glutamyl transpeptidase activity.