Background Social relations can be measured through: a) objective indicators, i.e. the number of social contacts in a given time interval or b) subjective indicators, i.e. feelings of loneliness. Comparing subjective and objective indicators in patients with psychotic and mood disorders may help to understand whether diagnosis-specific interventions should be designed for increasing their social relations. In this study we assessed social contacts outside home, work environments and mental health services, which may be increased by these interventions. We also explored feelings of loneliness which could influence readiness of patients to participate in interventions. Methods 100 patients in outpatient mental health care were asked to: a) list their social contacts; b) report their feelings of loneliness on a validated five point Likert scale. Multiple logistic regression models were used to test associations of diagnostic categories with: a) having more than one social contact in the previous week; b) reporting at least moderate feelings of loneliness. Results Patients had on average 1.7 (SD = 1.7) social contacts in the previous week (median = 1.0); 77 patients reported at least moderate feelings of loneliness. Patients with psychotic disorders (n = 30) showed a statistical trend towards having just one or no contacts in the week before the assessment (Odds ratio, OR = 2.246, p =.087). Patients with mood disorders were more likely to report at least moderate feelings of loneliness (OR = 2.798; p <.05). Conclusions Patients with psychotic disorders, compared to those with mood disorders, may be less likely to report feeling lonely although they tend to have less social contacts. Strategies to enhance social relations of people with psychotic disorders may include approaches to increase patients' drive to establish new social contacts and to emotionally support them in this process