The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of disorders in which patients usually have symmetrical weakness. Gray scale sonography (GSS) and power Doppler sonography (PDS) were done to detect and quantify the inflammatory process of the muscle. GSS and PDS scores were found to correlate with muscle biopsy and muscle enzymes. GSS is a useful approach to the assessment of IMM. PDS, enables detection of muscle vascularity and inflammation.