An 8-year-old girl with juvenile dermatomyositis (DM) developed dystrophic calcifications 26 months after diagnosis. She also had severe steroid induced bone loss (osteoporosis). The calcifications turned into generalized heterotopic calcinosis with an exoskeleton-like pattern, despite successful treatment of her myopathy with methylprednisolone and immunosuppressive drugs. She was subsequently treated with oral diltiazem (5 mg/kg/day) to control calcinosis and oral pamidronate (4 mg/kg/day) in addition to calcium and vitamin D supplementation, which she had been taking for 3 years. After 21 months of treatment, clinical and radiological examination revealed dramatic regression of the calcinosis. Bone mass reached normal levels, as determined by bone absorptiometry. Diltiazem alone or in combination with other drugs could be a useful therapy in patients with juvenile DM and pronounced calcifications.