Introduction: Gender differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising females vs. males, and in users of oral contraceptives (OC) vs non-users, but it is unknown if OC will influence tendon biomechanics of females undergoing regular training. Material and Method: 30 female athletes (handball players, 18-30 yrs) were recruited: Fifteen long-term users of OC (7.0±0.6 yrs) and 15 non-users (> 5 yrs). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor MVC to estimate mechanical tendon properties. Further, tendon cross-sectional area and length were measured from MRI images, and tendon biopsies were obtained for analysis of tendon fibril characteristics and collagen cross-linking. Results: Overall, no difference in tendon biomechanical properties, tendon fibril characteristics or collagen cross-linking was observed between the OC-users and non-users, or between the different phases of the menstrual cycle. In athletes, tendon CSA in the preferred jumping leg tended to be larger than the contra-lateral leg (p=0.09), and a greater absolute (p=0.01) and normalized tendon stiffness (p=0.02), as well as a lower strain (p=0.04) were observed in the jumping leg compared to the contra-lateral leg. Conclusion: The results indicate that long-term OC use or menstrual phases does not influence structure or mechanical properties of the patellar tendon in female team handball athletes.