In most developing countries breast feeding has been declining, particularly in metropolitan areas. A 1983 Contraceptive Prevalence Survey allowed an examination of breast feeding determinants in five metropolitan cities in Indonesia using the proportional hazards model. The median duration of breast feeding among women in these cities ranged from 14.9 to 23.6 months. The circumstances surrounding birth and mother's eduction were important determinants. Women who delivered at clinics or who were assisted by 'modern' birth attendants weaned from 1.45 to 2.38 times earlier than women who delivered at home or who were assisted by traditional birth attendants. Women with higher than elementary education weaned from 1.21 to 2.03 times earlier than women with less education. The short duration of breast feeding among women delivering in modem clinic settings has important policy implications. Promotion of satisfactory breast feeding, rooming-in, and strict prohibition of formula advertising will help to reverse the decline in breast feeding.