The excretion of breast milk was studied in six lactating women following the oral administration of a single trazodone tablet (50 mg). The milk/plasma ratio of trazodone based on area under the plasma and milk curves was small: 0.142 +/- 0.045 (mean +/- s.d.). Assuming that the babies would drink 500 ml 12 h-1, they would be exposed to less than 0.005 mg kg-1 as compared to 0.77 mg kg-1 for the mothers. It is concluded that exposure of babies to trazodone via breast milk is very small.