Background: Anterior disc displacement with reduction (ADDWR) is one of the most common temporomandibular disorders (TMDs). Many medications have been used for intra-articular injection in TMJ for treatment of ADDWR. One of the widely used medications is Hyaluronic acid (HA) due to its biological functions inside body joints. Collagen also has a very crucial role for keeping integrity of joints which has never been intra-articularly injected for treatment of any TMD. Aim of the study: The aim of this study is to compare the intra-articular injection of collagen versus HA as a treatment of Anterior disc displacement of TMJ. Methodology: 29 patients (30 joints) seeking treatment of ADDWR were randomly divided into two groups, group I patients were injected with collagen, while group II were injected with HA. The two groups were evaluated at 1 week, 1 month and 3 months post-operatively to the second injection according to Modified Helkimo's index for TMDs and according to lateral range of motion (lateral movement). Results: No significant difference was found between the two groups in any of the evaluation variables. Conclusion: the result confirms the crucial roles of HA as beneficial medication for treatment of ID and other TMDs. Also, it gives the chance for further investigations of collagen as a treatment of TMDs.