This study examined additive and interactive effects of callous unemotional (CU) traits and autism spectrum disorders (ASD) symptoms in relation to trait empathy, in boys with oppositional defiant disorder (ODD) or conduct disorder (CD). Participants were 49 boys with ODD/CD, aged between 7-12 years. Boys completed a questionnaire measure of empathic sadness and a broader questionnaire measure of affective and cognitive empathy. Parents and teachers reported on CU traits, and parents reported on ASD symptoms. In agreement with predictions, results reveal a negative association between CU traits and empathic sadness, particularly strong for ODD/CD boys with low levels of ASD symptoms. Results also reveal a negative association between ASD symptoms and cognitive empathy. Findings suggest that CU traits and ASD symptoms are associated with distinct empathy deficits with poor empathic sadness being more typical of CU traits than ASD symptoms.