Spirituality and religiousness have been shown to be highly prevalent in patients with schizophrenia. This study assesses the predictive value of helpful vs. harmful use of religion to cope with schizophrenia or schizo-affective disorder at 3 years. From an initial cohort of 115 outpatients, 80% were reassessed for positive, negative and general symptoms, clinical global impression, social adaptation and quality of life. For patients with helpful religion at baseline, the importance of spirituality was predictive of fewer negative symptoms, better clinical global impression, social functioning and quality of life. The frequencies of religious practices in community and support from religious community had no effect on outcome. For patients with harmful religion at baseline, no relationships were elicited. This result may be due to sample size. Indeed, helpful spiritual/religious coping concerns 83% of patients, whereas harmful spiritual/religious coping concerns only 14% of patients. Our study shows that helpful use of spirituality is predictive of a better outcome. Spirituality may facilitate recovery by providing resources for coping with symptoms. In some cases, however, spirituality and religiousness are a source of suffering. Helpful vs. harmful spiritual/religious coping appears to be of clinical significance.