This chapter deals with the discussion of abnormal heterotrophic calcification and ossification. Despite the regulatory mechanisms, calcium may be abnormally deposited in the extraskeletal system. In this process, no true bone matrix is formed. This is called as heterotrophic calcification. Tumoral calcinosis is uncommon inherited metabolic disease, which is characterized by extensive para- and periarticular calcification. Dysplasia epiphysealis punctata is a developmental anomalous condition characterized by discrete spots of calcification affecting cartilaginous structures. Renal osteodystrophy is the condition in which there are bone changes, which accompany chronic renal failure. Traumatic myositis ossificans is defined as a benign localized non-neoplastic fibrous osseous and proliferative lesion in the soft tissue and periosteum. As a result of a sprain or partial avulsion of upper femoral attachment of medial collateral ligament, calcification occurs which may range from minimal calcification to extensive myositis ossifications. Calcifying tendinitis of the rotator cuff is a common disorder of unknown etiology in which reactive calcification undergoes spontaneous resorption in the course of time with subsequent healing of the tendon.