We investigated the epidemiology, assessment and outcome of acute atraumatic limp in 243 children under the age of 14 years presenting to a paediatric accident and emergency department (AED) over a period of six months. Data were collected at presentation and medical notes were re-examined after 18 to 21 months. The incidence of limp was 1.8 per thousand. The male:female ratio was 1.7:1 and the median age 4.35 years. Limp was mainly right-sided (54%) and painful (80%); 33.7% of the children had localised pain in the hip. A preceding illness was found in 40%. The main diagnosis was 'irritable hip'/transient synovitis (39.5%); Perthes' disease accounted for 2%. Most patients (77%) were managed entirely in the AED. Acute atraumatic limp is a common problem in children presenting to the AED. Most can be safely managed there if guidelines are followed and will have a benign outcome. Further studies are needed to identify the role of preceding illness in the aetiology of acute atraumatic limp.