OBJECTIVES: To compare the effects of post-isometric relaxation, myofascial trigger point release and routine physical therapy on pain, disability and cervical range of motion in patients with acute mechanical neck pain. METHODS: The randomised control trial was conducted at the District Headquarter Hospital in Nowshehra, Pakistan, from July to December 2017 and comprised subjects of either gender aged 16-49 years with acute neck pain. They were randomised into three groups; post-isometric relaxation group 1, myofascial trigger point release group 2 and routine physical therapy group 3. Neck disability index, numeric pain rating scale and cervical goniometry were documented before intervention, after the first session and after 6 sessions in two weeks. Data was analysed using SPSS 21. RESULTS: Of the 60 patients, there were 20(33.3%) in each of the three groups. Mean age in group 1 was 32.25±9.56 years, group 2 2.35±9.05 years and in group 3 it was 32.75±7.82 years. Scores for neck disability index and numeric pain rating scale as well as rotation to right and left showed significant difference among the groups post-treatment (p<0.05). Within group analysis showed significant improvements in all parameters post-treatment in all the groups (p<0.0001). CONCLUSIONS: Acute mechanical neck pain treated with post-isometric relaxation technique had more and faster effect in decreasing pain and disability and in improving mobility.