Osteoarthritis (OA) is a degenerative disease that causes pain, loss of function and structural changes in the joint. Maintaining the joint range of motion and reducing pain has been the focus of OA treatment. With a better understanding of tissue regeneration and the mechanism of OA, the use of intra-articular applications has become widespread. The aim of our study is to form a general opinion about intra-articular applications of corticosteroid, hyaluronic acid (HA) and collagen in the treatment of OA. Current guidelines, meta-analyses, and randomized clinical studies that provide results and methods regarding intra-articular corticosteroid, HA and collagen applications in the treatment of OA were evaluated. The treatments of intra-articular corticosteroid, HA and collagen in OA are still continued controversially and there is no certain opinion or algorithm. Corticosteroids could be used to quickly relieve pain and restore function to the joint. Its effects are short-lived (1-3 weeks) and decrease significantly within three months. It is thought that HA may stimulate tissue regeneration. Thus, it could be recommended especially in patients with OA who have chronic pain and could be followed with non-surgical treatment options. Hyaluronic acid can significantly reduce pain and improve joint functions up to six months and its effects can last up to 12 months. The use of intra-articular collagen is not yet included in the guidelines as a recommendation. However, it is thought that collagen application may improve pain and functions for a long time and therefore may prolong the time until surgery.