Purpose: We reviewed the SLAP lesions and associated injuries, also evaluated a hypothesis that the type II posterior SLAP lesion is related with posterior rotator cuff tear and gives rise to the postero-superior instability. Materials and Methods: The patient recording papers, MRI, video and operation sheets were reviewed with the 28 SLAP lesions confirmed by the arthroscopy among 242 cases. Among these SLAP lesions, type II was 22 cases and classified to the anterior, posterior(16 cases), combined subtype(6 cases) based on the main anatomic location. There were 14 cases of the type II accompanying rotator cuff tear. The average follow-up(13 months) results were evaluated with the ASES and Rowe rating score after repair or debridement of the SLAP lesions. Results: In the type II lesions accompanying the rotator cuff tears(14 cases), the posterior(l0 cases) and combined type(4 cases), cuff lesions were all existed posteriorly. Also We could confirm the drive-through sign in the eleven cases, though did not check the disappearance of this sign after repair because of retrospective study. We could followed up the 22 cases, 18 cases(77%) were excellent or good, fair 3 cases(14%) and poor 1 case(4%). Also, type II lesions with the rotator cuff tear(14 cases) were showed better results in the repair(8 cases) than the debridement(6 cases) of the unstable type II with the cuff repair. Conclusion: The type II lesions were frequently associated with the cuff tear in the specific location. We could presume the possibility of postero-superior instability in the SLAP lesion with the cuff injuries. Also, satisfactory results could be experienced when the unstable SLAP lesions with the cuff tear were repaired at the same time.