Background: The hierarchy of power, dynamic of cohesion, and family structure might be affected in families with psychiatric patients. Objectives: This study aimed to compare the power, cohesion, and structure of healthy families and families with psychiatric patients. Methods: A cross-sectional study was conducted in Shiraz in 2018. Participants were 322 people from healthy families and families with schizophrenic, depressive, or bipolar disordered patients that were compared in terms of cohesion and hierarchy of power. Participants were selected by convenience sampling. Data were collected using the Family System Test, a clinically-derived figure placement technique. Data were analyzed using SPSS-19 with Chi-square and Kruskal Wallis tests at a significance level of less than 0.05. Results: There was no significant difference in terms of power between the families of healthy people and the families of patients with psychiatric disorders (P > 0.05). The family of patients with major depression had less cohesion (8.57 ± 2.2) than had the family of healthy ones (P =0.01). The structure of healthy families was more significantly balanced than that of other groups (P = 0.008). Conclusions: The results indicated that the power, cohesion, and structure of families can be affected by members with psychiatric disorders. Mental health care providers should take into account the mental health of families of psychiatric patients.