Attentional impairment is both a core characteristic of schizophrenia and a factor in producing poor outcomes in rehabilitative treatment. While cognitive rehabilitation interventions have demonstrated some success, the severity of some patients' attentional impairment is such that they cannot attend to material in these treatments, leading to unsatisfactory outcomes. In this paper, we report on the results of a behavioral intervention designed to increase attention span in the lowest functioning group of schizophrenia patients on a long-term inpatient unit. The treatment is based on social-learning procedures, especially the principle of shaping. Results indicate that chronic, treatment refractory patients with severe attentional impairment, including those with IQs near or within the mentally retarded range, can improve their attention spans to over 45 minutes with this treatment.