Prolongation of the prothrombin time owing to a transient reduction in factor VII activity is described in a 14-month-old child with organophosphate poisoning. Correction after vitamin K administration suggested an organophosphate-related effect on vitamin K-dependent factor VII activity. Historically, coagulation screening has not been routinely recommended after organophosphate intoxications. We suggest, however, that routine screening in such patients may be important. A brief review of organophosphate poisoning and the unique features of our case are presented.