Leaves of Eastern red cedar (Juniperus virginiana L. Cupressaceae) have been reported to contain podophyllotoxin, a pharmaceutical compound used to manufacture drugs for treatment of cancer, rheumatoid arthritis, genital warts, psoriasis, and multiple sclerosis. Podophyllotoxin content of leaves of immature, mature male, and mature female plants (similar to1.45 mg.g(-1)) was significantly higher than that of leaves of juvenile plants (0.60 mg.g(-1)). Sampling date also affected podophyllotoxin content. Leaves harvested in January and April exhibited higher podophyllotoxin contents (1.56 and 1.45 mg.g(-1), respectively) than leaves harvested in February and June(1.06 and 1.08 mg.g(-1) respectively). There was no obvious pattern or trend in the data due to sampling date. There was no significant interaction between plant type and sampling date. These results indicate that foliage of mature Eastern red cedar, a waste product of the lumber industry, could be a low-yielding, but relatively stable, source of podophyllotoxin.