Rotator cuff tears occur mainly due to overload of the tendons, which leads to a progressive degenerative process and to rotator cuff tears. Surgical treatment is indicated in more advanced stages of the lesion. Retear affects approximately 35% of patients. The goal of the present study was to investigate the effect of mononuclear cell transplantation in rotator cuff repairs in relation to patient functional recovery. Thirty patients with rotator cuff tear were divided into two groups and submitted to rotator cuff repair. In addition to the surgical procedure, the experimental group was submitted to transplantation of mononuclear bone marrow cells. One to two years post-op, both groups were submitted to evaluation of pain, amplitude of movement, retears, and isokinetic evaluation of flexion-extension movements, external and internal rotations, and abduction and adduction of the shoulder. The operated shoulder was compared to the healthy shoulder. Mann-Whitney test was used to evaluate the percentage improvement of the operated shoulder in relation to the healthy shoulder. SPSS (13.0) was used for statistical analyses; the level of significance was p<0.05. The control and the experimental groups presented near-normal values for the variables analyzed in the comparison between shoulders. However, the experimental group showed better results than the control group. Functional recovery of patients submitted to repair with mononuclear cell transplantation was different than that of controls: the incidence of retear was lower in the experimental group; also, the muscle torque and balance values were closer to the healthy shoulder values for the experimental group than the controls.