Alloplastic meshes are potential alternatives for reconstruction of irreparable rotator cuff tears. This study evaluates the biomechanical suitability at the tendon mesh interface of five different meshes. Twenty-five ovine infraspinatus tendons were repaired in five experimental groups (n = 5) with an alloplastic mesh. The control group was repaired with sutures (n = 5). Group 1 was repaired with a polypropylene mesh (Prolene), group 2 with a polypropylene/polyglactin mesh (Vypro), group 3 with a 1-mm thick ePTFE mesh, group 4 with a 2-mm ePTFE mesh (Gore-Tex), and group 5 with a 2.87-mm PTFE felt (Bard). The tendon-mesh interface was tested by a tensile testing machine until failure occurred. The control group failed at a mean (± SD) ultimate tensile strength of 98 ± 14 N with the sutures cutting out of the tendon. The Prolene mesh failed at 72 ± 12 N with the sutures cutting through the mesh. In the Vypro group, the repair failed at 75 ± 14 N. The 1-mm ePTFE mesh failed at 78 ± 9 N. The 2-mm ePTFE mesh failed at 109 ± 12 N and the PTFE felt at 111 ± 16 N with the sutures cutting through the tendon. There was a statistical significant difference (P < 0.01) between the 2-mm ePTFE mesh and the PTFE felt when compared with the other tested meshes. The ideal rotator cuff repair should possess high initial fixation strength and maintain mechanical stability over time. The 2-mm ePTFE mesh and the PTFE felt demonstrated significantly superior initial fixation strength at the mesh tendon interface when compared with the other tested meshes.