Background: Arthroscopic shoulder operations (ASS) are often associated with severe postoperative pain. Nerve blocks have been studied for pain in shoulder surgeries. Interscalene brachial plexus blocks (ISB) and an intra-articular injection (IA) have been reported in many studies. The aim of the present study is to evaluate the effect of ISB, a continuous cervical epidural block (CCE) and IA as a means of postoperative pain control and to study the influence of these procedures on postoperative analgesic consumption and after ASS. Methods: Fifty seven patients who underwent ASS under general anesthesia were randomly assigned to one of three groups: the ISB group (n = 19), the CCE group (n = 19), and the IA group (n = 19). Patients in each group were evaluated on a postoperative numerical rating scale (NRS), their rescue opioid dosage (ROD), and side effects. Results: Postoperative NRSs were found to be higher in the IA group than in the ISB and CCE groups both at rest and on movement. The ROD were $1.6{pm}2.3$, $3.0{pm}4.9$ and $7.1{pm}7.9$ mg morphine equivalent dose in groups CCE, ISB, and IA groups (P = 0.001), respectively, and statistically significant differences were noted between the CCE and IA groups (P = 0.01) but not in between the ISB and CCE groups. Conclusions: This prospective, randomized study demonstrated that ISB is as effective analgesic technique as a CCE for postoperative pain control in patients undergoing ASS.