The primary aim of the study was to investigate the prescribing patterns of selective serotonin re-uptake inhibitors (SSRIs) used on a chronic basis in a defined South African patient population, and to calculate the average prescribed daily doses (PDDs) of selected SSRIs. Prescription data for 2117 patients from various medical schemes who were using antidepressant drugs on a chronic basis were analysed retrospectively. More than 70% of all the patients using antidepressants were females. The tricyclic antidepressants (TCAs) and the SSRIs accounted for approximately 75% of all the antidepressants prescribed. The average age of the patients using SSRIs was 48.1 years (SD = 13.4 years). Fluoxetine was the most frequently prescribed SSRI, accounting for 63.3% of all SSRI prescriptions and 21.9% of all antidepressant prescriptions. The average PDDs of citalopram (23.9 mg), fluoxetine (21.7 mg) and paroxetine (21.1 mg) were slightly higher than their defined daily doses (20 mg for all three drugs). The average PDD of fluvoxamine (93.5 mg) was lower than the DDD (150 mg), but was still within an acceptable dose range. It was concluded that fluoxetine was clearly the drug of choice in treating chronic depression in this patient sample, and that the PDDs used in the patient population studied were in agreement with local and internationally acceptable dosage ranges.