Pyomyositis is rarely seen in temperate climates. Typically, it presents with the formation of an abscess requiring surgical drainage and it has been reported as a differential diagnosis for septic arthritis of the hip.

We describe the occurrence of pyomyositis of the iliacus muscle in a ten-year-old girl which was diagnosed by MRI and blood culture. Formation of an abscess did not occur despite marked focal inflammation and swelling of the muscle. Conservative treatment with antibiotics alone led to complete clinical and radiological resolution of the infection.

We could find no previous description of pyomyositis in a child in the British orthopaedic literature. Orthopaedic surgeons, particularly those with a paediatric interest, should be aware of this condition and its presentation, diagnosis and treatment.