The simultaneous arthroscopic exposure of the subacromial and intra-articular space of the shoulder is challenging in the presence of only partial-thickness rotator cuff tears. We present our experience and method of entering the joint through the opened rotator cuff interval from an anterosuperior portal between the coracoid process and anterior acromion. With moderate (approximately 30°) abduction and external rotation, the rotator interval opens readily, offering a view with the camera toward the anterior edge of the supraspinatus tendon. An anterior view on the anterior leading edge of the supraspinatus tendon is obtained, showing the subacromial space above and the glenohumeral space below the tendon, similar to the view in an aquarium. The rotator cuff can be elevated using a rod inserted intra-articularly from posterior, whereas anchors and other instruments may be inserted from lateral. This approach offers the advantages of full exposure of the posterior undersurface of the rotator cuff insertion; a convenient approximately 90° angle between the camera and instruments; and no need to change portals for anchor placement, tendon stitching, or suture handling. The objective of this Technical Note is to describe our arthroscopic repair approach (aquarium technique) to PASTA (partial articular supraspinatus tendon avulsion) lesions.