Successful treatment of tumoral calcinosis using continuous ambulatory peritoneal dialysis (CAPD) combined with hemodialysis is described. A 32-year-old male patient with a 2-year history of CAPD rapidly developed multiple metastatic calcification (tumoral calcinosis) adjacent to his fingers, elbows, and knee joints. Tests showed severe hyperphosphatemia, moderate hypercalcemia, and increased Ca-P product without elevation of intact parathyroid hormone. An enlarged parathyroid gland was not found by echography. In order to rapidly lower the excessive Ca and P levels, a combined therapy with CAPD and vigorous transient hemodialysis using a low-Ca dialysate was performed. In parallel, the patient was given calcitonin, bisphosphonate, and short-term Al to ameliorate the metastatic calcifications more effectively. The result was dramatic with disappearance of the tumoral calcinosis as well as improvement in subjective symptoms within a few months. The present case suggests that combined therapy with hemodialysis and CAPD using a low-Ca dialysate, together with Ca-modulating agents, can be effective in ameliorating tumoral calcinosis in patients on CAPD.