The authors report a rare case of piriformis pyomyositis, in a teenage rugby player, who was initially feverish and presented to us with low back pain, sciatica and inability to mobilise due to pain. Subsequent imaging investigations (MRI scan) revealed abscess formation in the piriformis muscle with compression effect on the ipsilateral sciatic nerve. A course of intravenous antibiotic therapy followed by oral antibiotics fully resolved his symptoms and returned inflammatory markers back to normal.