We tested the effectiveness of dihydroxyanthracenedione (DHAD) on cell growth of two human pancreatic carcinoma cell lines MIA PaCa-2 and PANC-1. At the level of ID50, the drug was almost equally effective against both cell lines. When the time exposure of MIA PaCa-2 cells to the drug was increased from 1 h to continuous exposure for 5 days, the ID50 was decreased about three-fold only (1.4 X 10(-8)M and 4 X 10(-9)M respectively). At the level of ID50 also the difference between 6 h exposure and continuous exposure for 5 days was minimal. In equimolar concentrations and with 1 h exposure, DHAD was more effective against MIA PaCa-2 cells than other chemotherapeutic agents including adriamycin, mitomycin-C, 5-FU, vincristine, vindesine, vinblastine, VP-16-213, bleomycin, cis-platinum, asparaginase and acivicin. In concentrations of 5 X 10(-7)M, DHAD caused about 40% inhibition of 14C-thymidine incorporation of MIA PaCa-2 cells. Treatment of MIA PaCa-2 cells with the ID50 of DHAD for 1 h caused retardation of cellular traverse, with the major effect appearing to be in G2 + M phase of the cycle. From these data DHAD appears to be a potent drug against human pancreatic carcinoma in vitro.