We experienced a case of A-59-year-old woman having autosomal dominant polycystic kidney disease with renal insufficiency associated with pelvic insufficiency fracture. On admission the pelvic bone compressed by the enlarged kidney and liver due to polycystic disease was demonstrated on the pelvic CT. Her bone mineral density was not significantly decreased contrary to our expectation. The prominent bone absorption in the endosteal and exosteal surface of the cortical bone was demonstrated in the bone specimen form iliac bone although the state of the cancellous bone and bone formation rate was normal. We performed the transcatheter embolization (TAE) to the kidney and liver to diminish their sizes. The fracture was rapidly improved and she could walk 6 months later after the TAE. In this case, we considered that the longstanding compression to the pelvic bone by the enlarged liver and kidney made the cortical and the binding of muscle/tendon and cortical bone fragile and it led to the pelvic insufficiency fracture.