A 1-month survey of the growth records of children attending Under Fives' Clinics in urban Sierra Leone was performed. Current weight for age of all attendees (n = 877) revealed an overall 17 per cent to be less than 80 per cent reference weight for age (RWA). The 0-5-month-old groups had the lowest incidence (8 per cent) less than 80 per cent RWA and the 12-23-month-old had the highest incidence (31 per cent) less than 80 per cent RWA. Episodes of weight loss greater than 2 per cent of previous recorded weight (n = 299) were analysed retrospectively. The peak incidence (32 per cent) of an episode of weight loss was again in the 12-23-month-olds. Overall respiratory and malarial symptoms were associated with the greatest number of episodes. Dysentery was the most important symptom in the 12-23-month-old (other than multifactorial), was associated with severe degrees of weight loss and had the highest incidence of slow progress following treatment. Episodes of weight loss attributed to helminthic infection became increasingly evident with age. Following treatment, 75 per cent of children had returned to their pre-episodic centile within 6 weeks.