Background: Family has a significant role on the mental health of its members, thus its contribution can also be distinguished in pathogenesis. Numerous mental diseases have also been linked to the family environment (FE) for maintenance and relapse. Aim: To assess the family environment among mentally ill patients. Design: Descriptive mixed design of both quantitative and qualitative methods was used in the current study. Setting: The study was conducted at Psychiatry and Addiction Prevention Hospital- Cairo University Hospitals. Sample: Purposeful sampling was employed in this study of 73 psychiatric patients. Tools: Three tools were used for data collection; Socio-demographic data sheet, Brief Family Environment Scale and the interview guide for the qualitative data. Results: Majority of participants were male (82.2%). Participants' age was 18-60 years. More than half (56.2%) of participants had positive family environment. There were statistically significant positive relationships between family environment and gender, chronicity of disease and occupation of mother. Regarding qualitative results, seven themes emerged from results. This involved physical family support, positive family expressiveness, family awareness, family cohesiveness, family positive relationship and environment, family controlling and functional family. Conclusion: Quantitatively and qualitatively findings of the study revealed unexpected results that there was positive family environment of mentally ill patients. Recommendations: Future studies could focus on how FE domains interact with family members' mental architecture and may ultimately lead to disease.