The nodular type of muscular sarcoidosis has been known to show characteristic MR findings: however, MR imaging features after steroid therapy have not been reported. A 48-year-old man with nodular type of muscular sarcoidosis is reported. Prior to steroid therapy, axial MR images showed peripheral increased signal intensity and central star-shaped decreased signal intensity. Coronal images showed an inner stripe of decreased signal intensity and outer stripes of increased signal intensity. After steroid therapy, axial images showed only the central star-shaped area of decreased signal intensity. Coronal images showed only the inner stripe of decreased signal intensity. It is important to know that the central area will continue to exist after steroid therapy.