To date, published reports assessing postoperative rehabilitation outcomes have been limited to retrospective studies and prospective observations. We present the first prospective randomized controlled study comparing postoperative dynamic versus static splinting outcomes of patients following extensor tendon repair. Patients who incurred simple and complete lacerations of their extensor tendons in zones V and VI were enrolled into the study and underwent either static splinting (n=17) or dynamic splinting (n=17) following primary acute repair of tendons. Patients were excluded if they were under-age (less than 18 years of age), had bony pathology(fractures or joint dislocations), had significant overlying soft tissue loss, were non-compliant with therapy instructions, or failed to return to regular visits. Total active motion and grip strength were evaluated for outcome measures. Total active motion was improved in the dynamic group when compared to the static group in the injured digits at 4 weeks (180.5° +/- 45° versus 131.3° +/- 61°; P=0.006), at 6 weeks (239° +/- 21.9° versus 205.5° +/- 53.4° ;P=0.048), at 8 weeks (247 °+/- 19.8° versus 216.3° +/- 36° ; P=0.051), but not at 6 months (253.1 °+/- 18.8° versus 250.5 °+/- 32° ; P=0.562). Similarly, total active motion averaged for all digits (injured and non-injured) of the involved hand was improved in the dynamic group over the static group at 4 weeks (209.8 °+/- 31.3° versus 140° +/-58.2°; P<0.001), at 6 weeks (241.5° +/- 17.2 °versus 217.1 °+/- 42.4° P=0.024), but neither at 8 weeks (249.6 °+/- 16° versus 234.8° +/- 24.5° P=0.215) nor at 6 months (252.3° +/- 14° versus 249.1° +/- 31° P=0.450). Grip strength outcomes demonstrated improved grip force for the dynamic group when compared to the static group at 8 weeks (81.3 +/- 18.0 % versus 59.2 +/- 20.4 %; P=0.004) but not at 6 months (89.6 +/- 5.6 % versus 82.1 +/- 22.0 %; P=0.595). Our findings suggest that dynamic splinting of simple, complete lacerations of the extensor tendons in zones V and VI provides improved functional outcomes at 4, 6, and 8 weeks but not by 6 months when compared to static splinting. Therefore, we recommend dynamic splinting of simple, complete extensor tendon lacerations in zone V and VI only to select patients who are motivated and desire earlier return to full functional capacity.