One of the most critical complications of bariatric surgery (BS), which has been widely discussed recently, is its adverse effects on the health of the bones and skeletal system. Studies show that bone mineral density (BMD) decreases significantly in the early years after BS Nutritional deficiencies are a common complication of BS that can last for months to years after surgery. For example, calcium absorption will significantly reduce after BS The role of gut hormones, endocrine factors, and adipokines in altering bone metabolism should never be overlooked. The available information and guidelines emphasize the periodic evaluation of BMD in patients undergoing BS The method of measuring BMD after BS is essential. DXA and quantitative computed tomography (QCT) are two convenient methods for measuring BMD. Many studies indicate a more detailed study of microarchitecture and cortical and trabecular bone mass with the help of QCT. The overall risk of fractures increases years after BS There are some recommendations for overcoming the adverse effects of BS on bone health. Endurance and resistance exercise after BS can help to mitigate BMD reduction and bone changes. In this review, we will explain each of these points in detail.