Pyomyositis is a bacterial infection of skeletal muscle. We describe the clinical case of a 77-year-old woman affected by gait disturbance, repetitive falls, low back pain and left thigh and groin pain, but without symptoms of systemic infection. Computed tomography and magnetic resonance imaging of the abdomen and pelvis showed abscesses in the left psoas and adductor brevis muscles. Investigations of urogenital tract and gastrointestinal system were normal. Systemic antibiotic treatment alone was not efficient, while surgical drainage improved the clinical picture. The aetiological organism, isolated from the abscess, was Staphylococcus aureus. We suggest that this patient had a primary pyomyositis rather than a secondary form. This is the first report of concomitant abscesses of psoas and adductor brevis muscles with early neurological involvement.