Background: Patellar tendon ruptures are infrequent but disabling injuries. Surgical treatment is the gold standard to obtain good outcomes, and numerous techniques have been described. Biomechanical studies report better results when augmented techniques are used. However, there is a lack of consensus regarding the best standard technique. Purpose/Hypothesis: The purpose of this study was to assess a cohort of patients with acute patellar tendon rupture that was surgically treated and to compare the clinical outcomes of 2 groups: isolated repair and biological augmentation techniques with autograft or allograft. It was hypothesized that the biological augmentation group would have better clinical outcomes than the isolated repair group. Study Design: Cohort study; Level of evidence, 3. Methods: All patients with acute patellar tendon rupture surgically treated in our center between 2016 and 2022 were retrospectively reviewed. Patient and rupture characteristics, surgical technique, clinical outcomes, and complications were recorded. The primary outcome was rerupture rate, and secondary outcomes were infection rate, stiffness >15 degrees of knee flexion deficit, and extensor mechanism lag >5 degrees. Results: The study included 34 patients with 36 operated knees (2 patients with bilateral rupture). The mean age was 44.9 years. Isolated repair was performed in 20 knees (55.6%), and 16 knees underwent repair and biological augmentation with autograft or allograft. Both groups were comparable in terms of their demographic characteristics. A statistically significant association was found between the type of surgery and tendon rerupture. Of the patients in the isolated repair group, 5 of 20 (25%) experienced a failure, whereas in the biological augmentation group, no reruptures were recorded (P = .031). However, no statistically significant associations were found between the type of surgery and other complications, such as the development of stiffness (P = .54), residual extension lag >5 degrees (P = .87), or the development of infection (P = .25). Conclusion: In this cohort of patients, biological augmentation reduced the rate of surgical failure for acute patellar tendon rupture without being associated with a higher risk of complications such as stiffness, residual extension lag, or the development of infection.