Objective: To study nonverbal social cue perception in children with attention-deficit/hyperactivity disorder (ADHD; n = 86), conduct problems (CP; n = 24), or both disorders (ADHD+CP; n = 63), as well as normal controls (n = 27). Method: Using a standardized test of receptive nonverbal processing abilities, participants were required to Interpret emotional cues from pictures of facial expressions and recordings of voices. Results: As predicted, children with CP and ADHD were significantly less accurate at interpreting emotions than normal controls. However, children with CP and ADHD differed in the type of errors made: the ADHD group's errors were generally random in nature, whereas the CP group tended to misinterpret emotions as anger. Contrary to our hypothesis, the ADHD+CP group performed better than the ADHD and CP groups, was as accurate as the control group, and displayed a unique pattern of errors. Conclusions: These results support the idea that social deficiencies associated with CP arise from a biased perception of emotion, whereas social problems in ADHD originate from a failure to attend to the appropriate cues of affect. The findings also support the theory that comorbid ADHD+CP is a distinct disorder.