Abstract: Introduction The biomechanical changes that arise after breast cancer increase the need for new rehabilitation programs. The aim of this study was to evaluate medium- and long-term effects of vibration therapy on pain intensity, range of motion, myoelectric activity, and muscle strength of post-surgical breast cancer women. Methods This controlled longitudinal clinical study was composed of 14 breast cancer women, who underwent vibration therapy treatment (VTG), and 14 healthy women, who constituted the control group (CG). The VTG performed ten 15-minutes sessions of vibration therapy on their affected upper limb. The volunteers were evaluated before and after treatment protocol, and three months later. Results We observed an attenuation of pain intensity after vibration therapy (p < 0.0001) and significant increase in range of motion during extension, abduction, and adduction movements of the horizontal shoulder. We noticed a trend in the reduction of compensatory movements, which activated the muscle contraction mechanism. The scapular dynamometer values for shoulder strength were significant. The VTG had less muscle strength than the CG in all situations: before treatment (p < 0.0001), after treatment (p = 0.0024), and 3 months later (p = 0.0008). The VTG increased muscle strength after treatment (p = 0.0005) and 3 months later (p = 0.0006). Conclusion Vibration therapy attenuated pain symptoms, improved shoulder movements, activated muscle contraction mechanism, and increased shoulder strength, which may be benefits of the conducted physical therapy.