Background: Collaborative interprofessional practices are essential in caring for people with complex mental health problems. Despite the difficulties of demonstrating positive impacts of interprofessional education (IPE), it is believed to enhance interprofessional practices. We aimed to assess impacts on patient satisfaction, self-reported psychological distress and mental health status in a psychiatric ward. Methods: We conducted a nonrandomized intervention study with patient satisfaction, psychological distress, and health status as outcomes. Mental health inpatients were referred to either an interprofessional training unit (intervention group) or to a conventionally organized ward (comparison group). Outcomes were assessed using the Short Form Health Survey (SF-36), the Kessler Psychological Distress Scale (K10), and the Client Satisfaction Questionnaire (CSQ-8). Results: The intervention group included 129 patients, the comparison group 123. The former group reported better mental health status than the latter; the postintervention mean difference between them being 5.30 (95% CI 2.71-7.89; p = 0.001; SF-36), with an effect size of 0.24. The intervention group patients also scored higher on satisfaction (mean difference 1.01; 95% CI 0.06-1.96; p = 0.04), with an effect size of 0.31. The groups' mean scores of psychological distress were identical. Conclusion: Our results support the hypothesized value of interprofessional training: intervention group patients reported higher scores regarding mental health status and satisfaction than did comparison group patients. As IPE interventions have rarely involved patients and fewer have taken place in practice settings, further research into both the processes and the long-term effects of IPE in mental healthcare is needed. Trial registration: The study was registered in ClinicalTrials.gov: NCT03070977 on March 6, 2017.