A cross-sectional survey, in 1991, of 3100 families in 45 contiguous villages in the Pune district of Maharashtra state showed that 456 under-5-year-olds had suffered an acute respiratory infection and/or diarrhoea during the previous 7 days. Significantly more boys (88.9%) than girls (76.5%) were treated by a registered private medical practitioner (odds ratio (OR) = 2.51). Referrals for further treatment were followed by parents significantly more often in the case of their sons (69.2%) than daughters (25%) (OR = 6.75). An average of Rs 35 (US$1 1.16) was spent on the treatment of a son, compared with Rs 23 (US$ 0.76) for a daughter. In general, parents were willing to travel a greater distance (> 2 km) to seek medical treatment for their sons. These differences persisted even after adjusting for severity of illness, parent's income, occupation and education, and the birth order of the child. Intervention programmes directed at under-fives would need to correct the bias against girls if equitable access to health care is to be achieved.