Background:There is a lack of studies of the size of burden associated with informal care giving in psychosis.Aims:To evaluate the objective and subjective burden of informal care giving to patients with psychoses, and to compare a diary and recall method for assessments of objective burden.Method:Patients and their informal caregivers were recruited from nine Swedish psychiatric outpatient centres. Subjective burden was assessed at inclusion using the CarerQoL and COPE index scales. The objective burden (time and money spent) was assessed by the caregivers daily using diaries over four weeks and by recall at the end of weeks 1 and 2.Results:One-hundred and seven patients (53% females; mean age 43 ± 11) and 118 informal caregivers (67%; 58 ± 15 years) were recruited. Informal caregivers spent 22.5 hours/week and about 14% of their gross income on care-related activities. The time spent was underestimated by two to 20 hours when assessed by recall than by daily diary records. The most prominent aspects of the subjective burden were mental problems.Conclusion:Despite a substantial amount of time and money spent on care giving, the informal caregivers perceived the mental aspects of burden as the most troublesome. The informal caregiver burden is considerable and should be taken into account when evaluating effects of health care provided to patients with psychoses.