Background. Several small-N, uncontrolled reports have demonstrated that the behavioral technique of attention shaping has significantly increased attention span among severely ill schizophrenia patients. Method. In this study, we evaluated the effectiveness of using an individually administered intervention for improving sustained attention, Attention Process Training (APT), followed by an attention-shaping procedure within the context of an ongoing skills training group. Patients were randomly assigned to receive either the APT and attention-shaping sequence (n = 18) or equivalent hours of treatment in the same intensive behavioral rehabilitation program (n = 13). Results. Results indicated dramatic improvements in attentiveness in the cognitive rehabilitation condition compared with the control condition, which demonstrated essentially no change in attentiveness over the 12 weeks of treatment. The attention-shaping intervention appeared to account for the majority of the effect. In contrast to the observational data, performance on neuropsychological tests was unaffected by the cognitive interventions. Conclusions. This two-phase intervention demonstrated effectiveness in promoting attentive behavior among chronic schizophrenia patients with severe attentional impairment.