The Diarrhoea Training Unit [DTU] of the University of Port Harcourt Teaching Hospital in Nigeria was established in 1991 and has, in addition to treating cases, been involved in training medical students, paediatric residents, health workers and mothers caregivers on correct case management of diarrhoeal disease. The accomplishment of the Unit over a defined time frame, January 1993 to December 1999, was evaluated by employing predetermined indicators and the data were analyzed by using the Statistical Package PEPI [Computer Programs for Epidemiologic Analysis Version 2.07a]. Eight thousand, four hundred and eighty-six cases (4557 males and 3929 females) of acute diarrhoea were treated. Those with severe dehydration were eleven times fewer in 1998 and eight times fewer in 1999 than in 1993. The number of Oral Rehydration Salts (ORS) sachets used in the Unit increased from 3064 in 1993/94 to 17,549 in 1998/99. There was no reduction in the number of cases treated, but the case-fatality rates dropped from 6 per 1000 in 1993 to 0.6 per 1000 in 1999 [likelihood ratio chi2 = 9.874, p = 0.02]. There was a significant reduction in the proportion of patients with bloody stools towards the end of the observation period [chi2(trend) = 82.60, 1 df, p = 0.000 (1.00E-19)]. These results indicate some positive impact on the severity of diarrhoea in the area, but preventive measures should now constitute the main thrust.