The authors report the history of two patients treated with CAPD who developed a progressive calcifying peritonitis (PCP). The symptoms include abdominal pain, impairment of bowel movements, sterile effluent dialysate and progressive development of peritoneal calcifications. The etiology of the PCP remains elusive, but dialysate with acetate, high peritonitis incidence and continuous lavage as treatment for peritonitis are suspected to play a role in its evolution.