Background: Engaging in social interaction has, for people with psychiatric disabilities, been shown to enhance well-being and the experience of meaning and to generally prevent the worsening of mental illness. Aim: The aim of the study was to investigate how day centre attendees differed from non-attendees regarding different aspects of social interaction and to investigate how occupational factors, including day centre attendance, and previously known predictors were related to social interaction in the study sample as a whole. Methods: A total of 93 day centre attendees and 82 non-attendees with psychiatric disabilities were examined regarding social interaction, subjective perception of occupation, activity level, sense of self-mastery and socio-demographic and clinical variables. Data were analysed with non-parametric statistics, mainly logistic regression. Results: Social support was mainly provided by informal caregivers such as family members. The day centre attendees had more social relations but did not experience better quality or closeness in their relationships than non-attendees. Important factors for social interaction were subjective perceptions of daily occupation, being married/cohabiting, self-mastery and severity of psychiatric symptoms. Conclusion: Alternative ways of enhancing social interactions in the community is needed, targeting the group’s feeling of satisfaction and value in daily life together with self-mastery.