Antipsychotic medications, while effective, often leave patients with ongoing positive and negative symptoms of schizophrenia. Guidelines recommend using cognitive behavior therapy (CBT) with this group. Clearly, mental health professionals require training and supervision to deliver CBT-based interventions. This study tested which antipsychotic-resistant patients were most likely to respond to brief CBT delivered by psychiatric nurses. Staff were trained over 10 consecutive days with ongoing weekly supervision. Training for carers in the basic principles of CBT was also provided. This article represents the secondary analyses of completer data from a previously published randomized controlled trial (Turkington D, Kingdon D, Turner T. Effectiveness of a brief cognitive-behavioural therapy intervention in the treatment of schizophrenia. Br J Psychiatry. 2002;180:523-527) (n = 354) to determine whether a number of a priori variables were predictive of a good outcome with CBT and treatment as usual. Logistic regression was employed to determine whether any of these variables were able to predict a 25% or greater improvement in overall symptoms and insight. In the CBT group only, female gender was found to strongly predict a reduction in overall symptoms (P = .004, odds ratio [OR] = 2.39, 95% confidence interval [CI] = 1.33, 4.30) and increase in insight (P = .04, OR = 1.84, 95% CI = 1.03, 3.29). In addition, for individuals with delusions, a lower level of conviction in these beliefs was associated with a good response to brief CBT (P = .02, OR = 0.70, 95% CI = 0.51, 0.95). Women with schizophrenia and patients with a low level of conviction in their delusions are most likely to respond to brief CBT and should be offered this routinely alongside antipsychotic medications and other psychosocial interventions.