Background: Mortality from acute diarrhoea and dehydration (AD/D) in children is high despite existing management guidelines. Aim: The aim of this study was to identify deficiencies in the management of AD/D by health staff and assess changes in management after a training intervention in a paediatric referral facility in Lagos, Nigeria. Methods: In a retrospective review of case notes, the management of AD/D was assessed using WHO guidelines as the standard. An e-learning module was developed that directly addressed deficiencies and was used to train health staff. Changes in the management of AD/D were assessed by re-auditing case notes. Results: There were learning needs among health staff in the management of AD/D. Altogether, 34 (97.1%) of 35 residents were trained. Training resulted in modest improvements in the number of children in whom nutritional status was assessed, use of oral rather than intravenous fluids for rehydration and reducing unnecessary laboratory tests. Training resulted in marked improvements in the correct volume of (pre-vs.post-training 6.3%vs.94.1%,P<0.001) and follow-up of fluid therapy (8.1%vs.98.0%;P<0.001), prescription of zinc (41.6%vs.85.1%,P<0.001) and providing advice on when to return after discharge (77.6%vs.96.0%,P<0.001). Although statistically significant, the minimal improvements in antibiotic use (43.8%vs.56.6%,P =0.03), re-starting feeds (10.6%vs.38.6%,P<0.001) and counselling about feeding (11.8%vs.33.7%,P<0.001) highlighted areas for further training. Conclusions: In low-resource countries, clinical auditing and training can significantly improve the management of illnesses that contribute to child deaths and identify areas where further training is required. [ABSTRACT FROM AUTHOR]