The incidence and length of breast feeding of LBW (less than or equal to 2500 grams) infants were investigated. A marked increase from 1979 to 1982 was noted: the incidence rose from 78% to 91% and the proportion of infants breast fed for 3 months rose from 54% to 67%. A breast feeding promotion programme did not influence the length of breast feeding of LBW infants within one year of the intervention. Smaller infants, those with RDS and those from lower social classes were breast fed less than others.