Background: Ultrasound (US)-guided Interscalene or Shoulder blocks are commonly used for Shoulder arthroscopic surgeries. Aim: The aim of this randomized study were to compare the block performance and onset times, effectiveness, incidence of adverse events and patient’s acceptance of US-guided Interscalene or Shoulder blocks. Methods: 68 patients were randomized to two equal groups: Shoulder block (SB) and Interscalene group (ISN). Each patient received a mixture containing 0.75% Ropivacaine. The block performance and latency times, surgical effectiveness, adverse events and patient’s acceptance were recorded. Results: The mean block performance time was 5.529 ± 1.022 mins in the ISN group and 8.559 ± 1.260 mins in the SB group. Onset of sensory block and motor block was early in ISN group. However, duration of sensory and motor block was higher in SB group. The total requirement of analgesic was higher in SB group and patients’ satisfaction was slightly more in ISN group. Also, ISN group had more complications than SB group. The haemodynamic parameters (H.R, systolic BP, diastolic BP, RR and SpO2) were recorded at 0, 4, 6, 12 & 24 hours. These parameters were all comparable in both the groups, thus statistically insignificant. Conclusion: Shoulder block can be considered in patients with Acute or Chronic respiratory distress, decreased pulmonary reserve, elderly patients, COPD patients and in patients with absolute contraindication to any degree of phrenic nerve block which almost always occurs in Interscalene nerve block.