Client motivation is regarded as a key to preventing violence behavior and positively affecting both patients and treatment staff in forensic psychiatric settings. We examined the correlation between client motivation for medical treatment and the quality of interprofessional teamwork. We surveyed 18 hospitalized forensic psychiatric patients using the IMI-J and CSQ-8J and 18 interprofessional teams from various professions using the r-CPAT, 6 and 12 months after the initial treatment. At 6 months, the correlation coefficients between the total r-CPAT scores and the total IMI-J and CSQ-8J scores were not significant. At 12 months, the correlation coefficients between the total r-CPAT scores and the total IMI-J or CSQ-8J scores were .33 and .11, respectively. The findings indicate that both clients’ motivation and the quality of treatment provided by the interprofessional team improved over time. However, this study also showed that the professionals’ subjective evaluation of the quality of interprofessional teamwork did not correlate with clients’ subjective evaluation of satisfaction. In order to achieve client satisfaction, it is essential for professionals to address clients’ needs in a timely manner and to prioritize effective communication to facilitate patient decision-making rather than merely providing advice.