In a pediatric residency training program, all residents viewed 15 slides of children's genitalia (eight normal, seven abnormal) with either a history specific for sexual abuse or one which was nonspecific. Three weeks later the same slides were viewed but with the alternate history scenario. The residents were asked if the physical findings were specific for sexual abuse. Sixty-four percent of residents completed both surveys. Correct response rate did not vary by gender or year of training. Responses were most often correct when the slide and history were normal. Responses were least accurate when normal historical information was presented with abnormal slides. A logistic regression model demonstrated that residents were less accurate when history and physical data did not agree. Reexamination of the data using areas under the Receiver Operating Characteristic (ROC) curve confirmed that residents performed on a less accurate ROC curve when the slide and history were incongruent. The authors conclude that incongruence between patient history and physical exam findings negatively affected this group of residents' ability to discriminate between abuse and nonabuse findings. Tables, references