We report the evaluation of a training programme on clinical management of infantile diarrhoea. The training programme was delivered through a series of on-site clinical courses offered to a selected group of physicians and nurses from 16 health units in Peru and a series of local workshops conducted in their own health units. The outcome of this training programme was assessed by pre- and post-tests, knowledge, attitude, and practice (KAP) questionnaires, and observational surveys. A significant improvement in medical knowledge about diarrhoea, in particular about the use of ORT and drug therapy, was observed. Although the observational surveys showed significant improvement in the use of ORT at health facilities (2.9% to 23.6%, p = 0.007) the rate observed was still low compared to the high level of knowledge on ORT that was demonstrated by the KAP questionnaires. A reduction of antibiotic prescription for inpatients with diarrhoea (85.7% to 64.8%, p = 0.025) was observed. The training programme was also effective in promoting the establishment of Oral Rehydration Units in the participants' health facilities.