The objective of the study is to investigate the extent of preventive and promotive health care in the ambulatory management of paediatric gastroenteritis in an incompletely immunised child using the simulated patient methodology. Only 44% of doctors explained to the fathers the nature of their child's ailment. 75% of clinicians prescribed oral rehydration solution but only 4% met the Gold Standard. The questionnaire survey showed that doctors rated immunisation as a very important health message to disseminate to all parents. But only 3% of doctors in the study advised parents to complete each child's immunisation once he is well. The extent of preventive and promotive health care in ambulatory paediatric practice in the Klang Valley is very low. (Copied from article).