Background: Poor control of pain affects quality of life and recovery after surgery that requires management of postoperative pain for better comfort, and outcome, with better and faster recovery.

Objectives: This investigation is designed to assess effectiveness of sub-scapularis (SC) and sub-omohyoid (SO) plane blocks for analgesia in post-operative arthroscopic shoulder surgery (ASS) and compare them with interscalene block (ISB).

Patients and methods: This Prospective randomized controlled double-blind study was performed on sixty cases of both sexes for arthroscopic shoulder surgery. The cases were allocated to: Group S: patients received SC and SO plane blocks in addition to general anesthesia (n=30). Group C: (control group) cases received ISB in addition to general anesthesia (n=30).

Results: Visual Analogue Scale (VAS) was matched until the 7th hour as it started to rise especially in the S group which was substantially elevated than the C group until 24 hours postoperatively. The mean values of onset times of complete sensory and motor blocks were statistically remarkably shorter in group S than in group C. patient's satisfaction score in the S group was statistically significantly higher than C group (8.2 ± 1.0 versus 7.6 ±1.1 in the S and C groups respectively)

Conclusion: Our findings demonstrated that subscapularis and sub-omohyoid blocks are more effective and safer analgesic technique than ISB for analgesia as it has a shorter time of onset of complete sensory and motor blocks with less total consumption of supplemental analgesia and less incidence of postoperative complications in unilateral elective arthroscopic shoulder surgery