Objectives The aim of this study is to demonstrate the importance of clinical diagnosis by comparing with preoperative physical examination and magnetic resonance imaging (MRI) images in patients who were arthroscopically diagnosed as having Superior Labrum Anterior-Posterior (SLAP) II lesions. Materials and Methods 134 patients, arthroscopically diagnosed as SLAP II, established the study group, and 200 patients who underwent shoulder arthroscopy for the other pathologies established the control group. Preoperative clinical examination of the patients, MRI findings, and the arthroscopic findings of the patients were recorded. Results Out of the patients diagnosed with a SLAP II lesion, 107 (79.9) of those had an MRI finding while only 60 (30%) of the control group had it. The O'Brien test results of the patients diagnosed with SLAP were positive in 111 (82.8%) while those diagnosed with intact superior labrum were positive in 132 (66%). Of the 134 patients with a SLAP II lesion, 89 (66.4%) had both O'Brien test positiveness and MRI finding, and 129 (96%) had at least one positive result of the O'Brien test or MRI examination Conclusion The O'Brien test and MRI examination are not capable enough to indicate a SLAP lesion one by one, because of the low sensitivity and specificity. But, combining the test with MRI findings provides more trustable information about the superior labrum.