BACKGROUND: Fear avoidance after musculoskeletal injury is avoiding activity due to fear of pain and contributes to persistent symptoms, depression, and disability. Little is known about fear avoidance for sport (athletic fear avoidance) in athletes with sport-related concussion (SRC). HYPOTHESIS: Athletic fear avoidance after SRC would be elevated at the start of rehabilitation, improve over time, and be associated with postconcussion recovery outcomes. STUDY DESIGN: Observational study. LEVEL OF EVIDENCE: Level 4. METHODS: Athletes in rehabilitation after SRC participated. Testing at initial and discharge visits and 6-month follow-up included Athletic Fear Avoidance Questionnaire (AFAQ), Postconcussion Symptom Scale (PCSS), Profile of Mood States (POMS), and Dizziness Handicap Inventory (DHI). Differences were explored in AFAQ score at initial testing based on sex or age (<18 or ≥ 18 years). Change in questionnaire scores over time was examined. Association of AFAQ score with other questionnaire scores was determined at each timepoint. RESULTS: A total of 48 athletes participated: 28 completed initial testing only (INITIAL ONLY), and 20 completed all testing (LONGITUDINAL). Across cohorts, the mean (SD) AFAQ score at initial testing was 24.3 (7.6) points, with no significant difference by sex or age. AFAQ, PCSS, POMS, and DHI scores improved in LONGITUDINAL; the effect size was large from initial to discharge testing (1.0, 1.0, 1.0, and 1.2, respectively) and variable from discharge to follow-up testing (0.52, -0.34, -0.08, and 0.02, respectively). AFAQ scores increased from discharge to follow-up in 3 athletes and were consistently above the mean value in 2 athletes. AFAQ score was significantly correlated to the other questionnaire scores at each timepoint (range, r = 0.36-0.75). CONCLUSION: Athletic fear avoidance was elevated at the start of SRC rehabilitation, improved over time in most patients, and was associated with postconcussion symptoms, mood, and disability. CLINICAL RELEVANCE: Athletic fear avoidance may impact recovery after SRC.