Although failure to thrive has been documented as a major problem in babies with congenital HIV infection, there is little information on whether HIV affects growth in older children who become infected with HIV. The growth of 27 haemophilic boys, in whom HIV seroconversion was recorded between 1981 and 1986, has been assessed to see if the pattern changed after seroconversion. Height and weight recordings were analysed over a mean period of 9.2 years with a mean duration from HIV seroconversion of 4.5 years (range 2 to 6 years). Height standard deviation scores and ratio of weight to 50th centile for chronological age were calculated. No significant change in growth pattern as judged by height and weight has been observed within this group of boys after HIV seroconversion. Growth assessment continues to be evaluated to see if further progression of HIV disease changes growth pattern in these boys.