© 2021 MA Healthcare Ltd. All rights reserved.Background/Aims Shoulder problems are common in the general population. The aim of this research was to compare the short and long-term effects of trigger point deep friction massage and trigger point dry needling therapy on rest, activity, and the intensity of night shoulder pain and shoulder internal rotation in Subacromial Pain Syndrome. Methods Out of 73 outpatients diagnosed with Subacromial Pain Syndrome, 40 were selected according to agreed criteria and were randomly assigned to two groups. A total of 19 patients received trigger point deep friction massage and 21 received trigger point dry needling therapy. The trigger point deep friction massage group received treatment over 3 weeks and the trigger point dry needling therapy group received treatments over 4 weeks. Both groups received six treatment sessions and a programme of post-treatment exercises. The shoulder internal rotation angle was measured using a goniometer, and pain intensities were measured using a visual analogue scale before the first session, after six sessions and after 1 year. Results According to both the short- and long-term data, significant improvements were seen in both groups for all parameters. However, when the groups were compared, no significant difference was found between the two interventions, although the trigger point deep friction massage intervention showed earlier improvements as the treatments could be carried out in 3 weeks, rather than the 4 weeks required for the trigger point dry needling therapy sessions. Conclusions Both trigger point deep friction massage and trigger point dry needling therapy are effective in improving pain and shoulder internal rotation. Both groups maintained significant clinical improvement throughout the year. Although both interventions produced good results, trigger point deep friction massage treatments were completed in a shorter time and so demonstrated earlier improvements. Therefore, Trigger point deep friction massage may be regarded as the preferred option, particularly as no equipment is needed and is a non-invasive method of treatment.