We report an effective technique of arthroscopic portal placement for rotator cuff repair of the shoulder. The differential portals are placed depending on the location of the tear. After the glenohumeral arthroscopic examination, the subacromial bursoscopy is performed through the same posterior skin portal. With the rotator cuff tear in view, a spinal needle is inserted to the center of the tear, 3 cm from the lateral margin of the acromion (middle working portal). Another spinal needle is then inserted into the posterior lip of the tear, 1 cm from the lateral margin of the acromion (rear viewing portal). The rear viewing portal provides a good downward en-face view of the tear, and the middle working portal allows better access to the anterior and posterior margins of the cuff tear than the usual posterior and lateral portals do. This differential portal placement with respect to the location of the rotator cuff tear ensures superior access for arthroscopic repair of rotator cuff tears.