Lithium chloride aversive conditioning to reduce raccoon (Procyon lotor) predation of loggerhead turtle (Caretta caretta) nests was tested under laboratory and field conditions. A total dosage of 1.0 g was determined to produce side effects (diarrhee and emesis) soon after ingestion, and the negative taste reaction to the drug was eliminated when a dosage level of 0.25 g/egg was administered. In separate phases of laboratory testing on 37 raccoons, an aversive conditioned response was observed in only a few individuals. During field testing, there was no significant difference (t = 1.11; P> .05) between the depredation rate on turtle nests before and after a 3-week period of LiCI treatment. Despite the administration of the drug at an undetectable dosage level with resultant physiological side effects, an effective psychological association of food with illness was not made by raccoons. The use of LiCI as a management technique to reduce raccoon depredation of sea turtle nests appears to have little utility.