Postoperative analgesia is one of keys to success of ambulatory surgery. Interscalene block (ISB) is known as being a reference for loco-regional anesthesia (LRA) but has serious risks and many contraindications. The suprascapular block (SSB) is an alternative to ISB, simple, safe and inexpensive. The suprascapular nerve innervate infra and supraspinatus tendons. The hypothesis of the study was that the SSB was as effective as the ISB on postoperative analgesia after arthroscopic repair of these tendons. A randomized single-blind controlled study was performed in 2013-2014. The inclusion criteria were to repair intraoperatively confirmed damage of these tendons, with or without associated procedures and informed consent. The exclusion criteria were a previously operated shoulder, a lesion of the subscapularis tendon and a known allergy to local anesthetics. The primary evaluation criterion was the average of shoulder's pain during the first 24 hours, assessed by the patient on a visual analogical scale (VAS), from 0 to 10. Secondary evaluation criteria were the complications of LRA, the use of analgesics in the recovery room until the seventh postoperative day and pain (VAS) during the first week. An Institutional Review Board approved this study. 59 patients met the intraoperative criterion of inclusion ; the mean age was 59 ± 8.8 years. There was not statistically significant difference between SSB group and ISB group on the mean pain for the first 24 hours (p=0.28) and for the first seven days (p=0.05). But the ISB group was significantly less painful at the recovery room (p=0.009). Analgesic consumption was comparable between the two groups. One complication (pneumothorax) related to the ISB was observed. The SSB is less invasive and as effective as the ISB in early analgesia after arthroscopic repair of supra and/or infraspinatus tendons.