Observations were made of 996 encounters between children with diarrhoea and practitioners (28 paediatricians, 62 general practitioners) in Karachi, Pakistan. Oral rehydration salt (ORS) was prescribed in more than 50% of encounters by 53% of general practitioners (GPs) and 61% of paediatricians. Sixty-six percent of GPs and 50% of paediatricians prescribed antibacterials, 60% of GPs and 28% of paediatricians prescribed antidiarrhoeals and 39% of GPs and 32% of paediatricians prescribed antiamoebics in more than 30% of their encounters. Looking at all the encounters, we observed that ORS was prescribed in 52 and 51%, antibacterials in 41 and 36%, antidiarrhoeals in 48 and 29%, and antiamoebics in 26 and 22% of encounters by GPs and paediatricians, respectively, Cotrimoxazole was the most frequently prescribed antibacterial by both types of practitioners. Antidiarrhoeals were prescribed more often by GPs than by paediatricians. In 77% of their encounters, GPs dispensed drug formulations known as "mixtures' made in their own dispensing corners. The mean duration of encounters between patients and GPs was 3 +/- 2 minutes and between patients and paediatricians was 9 +/- 4 minutes. These results indicate inadequate prescription of ORS and excessive prescription of antibacterials, antidiarrhoeals and antiamoebics. Intervention strategies need to be planned to improve the prescribing practices of both groups.