Psychopathic tendencies are associated with difficulties in affective theory of mind (ToM), that is, in recognizing others affective mental states. In clinical and non-clinical adult samples, it has been shown that where psychopathic tendencies co-occur with schizophrenia spectrum disorders, the impairing effects of psychopathic tendencies on ToM are attenuated. These effects are yet to be examined in adolescents. We examined if the impairing effect of psychopathic tendencies on affective ToM was attenuated with increasing severity of schizotypal personality disorder (PD) in a sample of 80 incarcerated adolescent boys. We showed that the impairing effect of psychopathic tendencies on the recognition of neutral mental states, but not positive or negative mental states, was evident when the relative severity of schizotypal PD was low. However, with higher scores on both measures, we observed better performance in judging neutral mental states. The preservation of affective ToM in adolescents who show elevations in psychopathic tendencies and schizotypal PD may enable them to manipulate and extort their victims for personal gain. Our results emphasize the need to consider comorbidity in clinical case formulation when working with adolescents with conduct problems and psychopathic tendencies. More broadly, our results also suggest that the pattern of social cognitive abilities associated with co-occurring psychopathology does not always conform to an often-theorized double-dose of deficit hypothesis.