Enhancing cognitive performance to improve functioning in schizophrenia is a fundamental research priority. Previous investigations have demonstrated that various types of cognitive training (CT) can improve neuropsychological performance, psychosocial functioning, and psychiatric symptom severity. However, there is limited information about individual differences that may predict CT response and adherence to treatment. The purpose of this study was to identify who is likely to drop out of this type of study as well as this type of intervention and to explore individual factors predicting treatment outcome. Participants included 89 outpatients diagnosed with a primary psychotic disorder who enrolled in a randomized controlled trial of compensatory CT and were assessed at baseline, 3 months (posttest), and 6 months (follow-up). Study completers had more formal education and lower daily doses of antipsychotic medications than did dropouts with no CT exposure, but the groups did not otherwise differ. There were no significant differences between participants who completed CT and those who began CT but later dropped out. CT-associated improvement was correlated with worse baseline scores on measures of cognitive performance, symptom severity, functional capacity, and self-rated quality of life, cognitive problems, and strategy use. These results suggest that those with lower baseline functioning may have more room to improve following CT. The pattern of correlations in this sample indicated that many types of individuals can improve with CT treatment, including older patients.