Objectives Previous research has employed the Transtheoretical Model of Change (TIM) (Prochaska & DiClemente, 1982, 1984) to understand the processes of change. This study investigates whether self esteem, distress, locus of control and social desirability are associated with, and can predict readiness to change in mentally disordered offenders, consistent with processes identified by TIM. Design and Method A cross-sectional design was employed to assess 73 mentally disordered offenders, with a diagnosis of psychosis, who completed self-report measures: Rosenberg's Self Esteem Inventory (RSES), the Outcome Questionnaire (OQ-45), Marlowe-Crowne Social Desirability Index (MCSDI) and Rotter's Locus of Control (RLoC). Readiness to Change was measured by the University of Rhode Island Change Assessment (URICA) (DiClemente and Hughes, 1990). Results All participants were categorised in the precontemplative stage of change. Participants with high readiness to change report higher symptom distress, lower self esteem and lower social desirability than those with low readiness to change. Regression analyses identified that self-esteem was the only significant predictor of readiness to change. All participants were found to have an external locus of control relative to previous research. Conclusions The results identify a potential model for readiness to change that could inform interventions, with a focus on self-esteem, to improve readiness to change.