Background and Objectives: Awareness of temporomandibular joint disorder (TMD) is fairly concerning in management of physiotherapy as patients often seek for treatment from orthodontics when pain become their main concerns. In this case, cervical aspects are often overlooked in the treatment of temporomandibular joint disorder. This study aims to determine the effect of cervical extensor strengthening on severity of temporomandibular joint disorder. Methods: A randomized controlled trial study was carried out for 4 weeks to determine the effect of cervical extensor strengthening on severity of temporomandibular joint disorder among university students. A total of 40 participants were recruited via convenient sampling method. Subjects were randomly assigned into two groups: experimental group (E) and control group (C) through lottery randomization. Subjects in experimental group were instructed to perform 1 set of cervical extensor strengthening with 10 repetitions and goldfish exercises whereas subjects in control group were asked to perform goldfish exercises only. A pre-test and post-test severity of TMD, maximal mouth opening and maximal isometric cervical extensor strength were measured for both groups. Results: After 4 weeks of training, there was significant difference in pre-test and post-test severity of TMD and maximal mouth opening for both E and C group. On the other hand, there was significant difference of pre and post-test of maximal isometric cervical extensor strength in experimental group. There was no significant difference in post-test for severity of TMD (p=0.67), maximal mouth opening (p=0.21) and maximal isometric cervical extensor strength (p=0.40) between two groups. Conclusions: The study concluded that, 4 weeks of anti-gravity cervical extensor strengthening exercises protocol showed there was no significantly difference of the severity of TMD and maximal mouth opening between both control and experimental group. On the other hand, goldfish exercises showed significant improvement of maximal mouth opening and reduction in severity of TMD after 4 weeks of intervention period.