Context: Posterior calf stretching is believed to improve active ankle dorsiflexion range of motion (AADFROM) after acute ankle-inversion sprain. Objective: To describe AADFROM at baseline (postinjury) and at 2-wk time periods for 6 wk after acute inversion sprain. Design: Randomized trial. Setting: Sports clinic. Participants: 11 men and 11 women (age range 11–54 y) with acute inversion sprain. Intervention: Standardized home exercise program for acute inversion sprain. Main Outcome Measure: AADFROM with the knee extended. Results: Time main effect on AADFROM was significant (F3,57 = 108, P < .001). At baseline, mean active sagittalplane motion of the ankle was 6° of plantar flexion, whereas at 2, 4, and 6 wk AADFROM was 7°, 11°, and 11°, respectively. Conclusions: AADFROM increased significantly from baseline to week 2 and from week 2 to week 4. Normal AADFROM was restored within 4 wk after acute inversion sprain.