We report clinical and laboratory data from 32 children with benign acute childhood myositis (BACM), children who presented with calf tenderness and gait abnormality. Laboratory evidence of a viral infection was evident in 23 patients, while serum creatine phosphokinase was uniformly increased (558 to 6800 U/L). Twenty-five patients (78.1%) were given a diagnosis other than BACM by their general practitioner or paediatrician. All patients made a rapid recovery within one week. We conclude that BACM should be encountered among the main causes of sudden-onset gait abnormality in young children.