Several theories suggest that posttraumatic intrusive symptoms are central to the relationship between childhood trauma (CT) and hallucinations and delusions in psychosis. Biased selective attention has been implicated as a cognitive process underlying posttraumatic intrusions. The current study sought to test theories of the relationship between childhood sexual abuse (CSA), hallucinations and delusions, posttraumatic intrusions, and selective attention in first-episode psychosis (FEP). Twenty-eight people with FEP and 21 nonclinical controls were assessed for CT and psychotic and posttraumatic stress symptoms and completed an emotional Stroop test using CSA-related and other words. Those with FEP and CSA had more severe hallucinations and delusions than those with FEP and without CSA. They also reported posttraumatic intrusions at clinical levels and showed selective attention to CSA-related words. The results are consistent with the posttraumatic intrusions account of hallucinations and delusions in those with CSA and psychosis.