PIP: There has been a widespread epidemic of hypokalemia of unknown cause in China since 1964. The symptoms are fatigue and muscle weakness followed by flaccid paralysis with lowered serum potassium level. This hypokalemia is different from that described in medical textbooks. A large number of patients suffering from hypokalemic paralysis were found to live in certain cotton growing districts of China. After repeated epidemiological survey, most investigators concluded that the incidence of hypokalemic paralysis in those districts was related to subjects' use of crude cottonseed oil as their cooking oil. Crude cottonseed oil contains gossypol, a potential male antifertility agent postulated by Qian et al. in 1980 to be capable of inducing hypokalemia. Accumulated data, however, do not support the hypothesis of gossypol-induced hypokalemia. The authors reanalyze evidence on the notion of gossypol-induced hypokalemia and suggest that an unknown cause rather than gossypol was the true cause for the observed hypokalemia in gossypol takers. The issue of gossypol-induced hypokalemia remains unsettled and in need of thorough reconsideration. Meanwhile, the clinical trial for gossypol in China has been abandoned along with the worldwide pursuit of gossypol as a male antifertility agent. Many results on the subject conducted in China are brought together, some of which are not available in the usual western scientific literature.