Rehabilitation overadherence is a form of nonadherence in which individuals exceed practitioners' guidelines regarding the rehabilitation of their injury resulting in enhanced risk for re-injury and prolonged recovery (Granquist et al., 2014). Overadherence is common among overly-motivated injured athletes with intense personalities (Niven, 2007). This suggests that perfectionism may be a meaningful predictor of rehabilitation overadherence among injured athletes. This study utilized the 2 × 2 model of perfectionism (Gaudreau & Thomspon, 2010) to investigate this claim. Injured athletes (N = 82; Mage = 27.45 years, SD = 10.88) currently undergoing supervised rehabilitation completed measures of two perfectionism dimensions (personal standards and evaluative concerns) and four overadherence risk-factors (effortful healing, expedited rehabilitation, inclinations to overadhere, and normalization of pain). Multiple regression tested whether the perfectionism dimensions interacted to predict each overadherence risk-factor. No significant effects were found for effortful healing and expedited rehabilitation. A significant main effect (B = 0.17) indicated that higher levels of evaluative concerns predicted greater inclinations to overadhere. A significant interaction effect (B = -0.07) identified a similar relationship between evaluative concerns and normalization of pain, but specified that this relationship was greatest when personal standards were low. Findings are interpreted in-line with the 2 × 2 model's hypotheses and identified as initial evidence of associations between perfectionism and sport injury rehabilitation overadherence. In discussion, we speculate as to why relationships were evident for some overadherence risk-factors, but not others, elaborate on the role of evaluative concerns perfectionism in overadherence, and suggest practical implications for practitioners.