Introduction: Shoulder impingement syndrome is one of the most common musculoskeletal injuries of upper limb leading to physical medicine & rehabilitation (PM&R) OPD visit. Over decades of use, literature shows lower infiltration and efficacy of intra-shoulder joint steroid in some etiological subtypes of impingement syndrome. Interestingly, major afferent supply around shoulder joint is by suprascapular nerve. This study is a sincere attempt to look for efficacy of suprascapular nerve block (SSNB) over subacromial corticosteroid injection in shoulder impingement syndrome. Aims and objectives: To look for improvement in visual analog scale (VAS) and shoulder pain and disability index (SPADI) after subacromial steroid injection or SSNB in shoulder impingement syndrome and to compare efficacy of both the approaches. Materials and methods: A randomized control trial was performed in the Department of Physical Medicine and Rehabilitation, IPGMER; SSKM Hospital, West Bengal, India from August 2017 to February 2018 recruiting total 70 patients with conservative treatment failed, ultrasonography (USG) confirmed Neer stage I and II symptomatic (VAS >5) impingement patients without any coagulopathy, supraspinatus tear or history of intra-articular steroid injection in the last 3 months. After Ethics Committee clearance, two groups of 35 patients each were made randomly. Group I received steroid injection by subacromial approach. Suprascapular nerve block was performed in the second group of patients. Assessment by VAS and SPADI was performed before intervention, 2 weeks, 4 weeks, and 12 weeks after injection. Results: Statistically significant improvement was seen in both the groups with better outcome with SSNB at longer follow-up (p = 0.003). Conclusion: Suprascapular nerve block is a better alternative both in short- and long-term to subacromial steroid injection in the management of shoulder impingement syndrome.