Low bone mineral density (BMD) is one of the risk factors for bone fracture. The incidence of bone fracture is highest among patients with chronic renal failure. There is little data about the BMD of patients undergoing chronic peritoneal dialysis (PD). In addition, dialysis patients with low vitamin D levels are at increased risk of early mortality. We investigated the incidence of osteopenia/osteoporosis and relationship between BMD and vitamin D levels in 28 peritoneal dialysis patients. Bone densitometry was studied by dual-energy x-ray absorptiometry (DEXA). Bone mass was classified as normal, osteopenic, or osteoporotic according to World Health Organization criteria. Serum 25-hydroxyvitamin D (25OHD) levels were measured in all patients. Of the 28 patients, 25.7% had osteoporosis and 27.9% had osteopenia. Mean 25OHD levels were 50.4±28 nmol/L. Twelve patients (42.9%) had vitamin D insufficiency, eight (28.6%) had vitamin D deficiency and three (10.7%) had severe deficiency. In conclusion, these results indicated that 53.6% of our chronic PD patients have subnormal bone mass. In addition, vitamin D insufficiency and deficiency are very common in peritoneal dialysis patients.