Management of TMDs with occlusal splint is a reversible, non- invasive modality which causes minimum damage to tissues, when compared to other irreversible treatment modalities. Objectives of this study is to assess the effectiveness of flat occlusal splint in patients with anterior disc displacement without reduction by evaluating reduction in pain and improvement in mouth opening. 35 participants with mean age 35 years who does not have any systemic diseases and not undergoing treatment for ADD without reduction were selected for study. After recording pain score on VAS scale and maximum mouth opening, flat occlusal splint was fabricated for maxillary arch. Patients were advised to wear the splint for all the time except on meal times. Maximum mouth opening and pain score were again evaluated after 3 weeks. Statistical results showed that there is highly significant reduction in pain score and increase in maximum mouth opening. Mean VAS score before treatment was 7.26±0.88. After treatment with splint therapy, VAS score was reduced to 2.94±1.41. The mean value of maximum mouth opening before treatment was 23.09±4.25. After treatment with splint therapy, it was increased to 30.37±5.43. Both parameters had p value <0.001, which is highly significant statistically. Significant reduction in pain score and improvement in mouth opening noted after using flat occlusal splint in patients having ADD without reduction. However, further studies are needed on a long term basis for better results.