Case report. -A 5-year-old girl was hospitalised for fever,abdominal and lumbar pain,associated with general impairment state and a whitlow. One of the blood cultures and CSF grew A β ; haemolytic Streptococcus,muscular echography and MRI showed paravertebral myositis,which was complicated by an epidural abscess. The outcome was good with medical treatment alone. Discussion. -Streptococcal myositis is a rare and severe skeletal muscle infection caused by A β haemolytic Streptococcus. It is characterized by a muscle necrosis,without abscess formation. It has to be distinguished from pyomyositis,usually caused by Staphylococcus aureus,where a muscle abscess occurs,which must be treated by surgical drainage and antibiotics. Prognosis of this infection is poorer than other muscle infections such as pyomyositis,with a high mortality rate. The diagnosis is difficult and often delayed. Practitioners should keep in mind this diagnosis,even if symptoms are non specific,in front of an undetermined infectious syndrome associated with pain,and make an echography or nuclear magnetic resonance imaging to confirm the diagnosis. Case report. -A 5-year-old girl was hospitalized for fever, abdominal and lumbar pain, associated with general impairment state and a whitlow. One of the blood cultures and CSF grew A β; haemolytic Streptococcus, muscular echography and MRI showed paravertebral Myositis, which was complicated by an epidural abscess. The outcome was good with medical treatment alone. Discussion. - Streptococcal myositis is a rare and severe skeletal muscle infection caused by A beta haemolytic Streptococcus. It is characterized by a muscle necrosis, without abscess formation It has to be distinguished from pyomyositis, usually caused by Staphylococcus aureus, where a muscle abscess occurs, which must be treated by surgical drainage and antibiotics. Prognosis of this infection is poorer than other muscle infections such as pyomyositis, with a high mortality rate The diagnosis is difficult and often delayed. Practitioners should keep in mind this diagnosis, even if symptoms are non specific, in front of an undeterm ined infectious syndrome associated with pain, and make an echography or nuclear magnetic resonance imaging to confirm the diagnosis.