Context Patellar tendinopathy (PT) is a highly prevalent overuse injury in volleyball. However, little is known about whether and how the risk for developing PT is increased through fatigue-induced alterations during repetitive jump-landing activities in volleyball. Objective The purpose of this study was to explore fatigue-induced risk factors for PT during a spike jump-landing task in volleyball. Design Prospective cohort study. Setting Three-dimensional biomechanical laboratory screening. Patients or Other Participants Seventy-nine adult male volleyball players. Main Outcome Measure(s) At baseline (preseason), 3-dimensional full-body kinematics and kinetics were collected while participants performed a spike jump before and after a volleyball-specific fatigue protocol. Throughout the season, players were followed for the occurrence of PT, and a survival analysis with competing risks was performed to identify significant predictors for the development of PT (P < .05). Results During follow-up, 10 of the 79 players developed PT (13%). Players with significantly less hip flexion during the horizontal landing/push-off phase of the spike jump after fatigue were at higher risk for developing PT (hazard ratio = 0.898; 95% CI = 0.826, 0.977; P = .023), as were players with a significantly more elongated rectus femoris muscle-tendon unit (hazard ratio = 3.258; 95% CI = 1.136, 9.343; P = .032). Conclusions Despite the low (injured) sample size of this study, preliminary research findings indicate less hip flexion and more elongated rectus femoris muscle-tendon units during landing after fatigue as potential risk factors for developing PT. Practitioners may wish to focus future prevention programs for PT on hip-specific exercises and technique modifications (eg, more hip flexion during landing) under fatigued circumstances.