The skeleton is one main sites of metastasis of solid tumors, and metastatic bone disease are most common malignant disease of the bone. The diagnosis and assessment of bone metastases require integrated multimodality combined approach of different diagnostic methods, including both different radionuclides that radiological techniques such as X-rays, CT and MRI. In this scenario the nuclear medicine gives a significant contribution to the evaluation of skeletal metastases. In this article we will analyze the main approaches.