Context: Tightness or lack of flexibility of several muscles of the thigh has been associated with patellofemoral joint pain. A tight iliotibial band can lead to laterally located patella and an abnormal patellar tracking pattern. Diacutaneous fibrolysis (DF) is commonly used to reduce muscle tightness, but no studies have evaluated the effects of this technique in the treatment of patients with patellofemoral pain syndrome. Objective: To assess the effect of DF on patellar position in patients with patellofemoral pain syndrome. Design: A single-group, pretest–posttest clinical trial. Setting: University of Zaragoza. Participants: A total of 46 subjects with patellofemoral pain (20 males, 26 females; age: 27.8 [6.9] y). Intervention: Three sessions of DF. Main Outcome Measures: Patellar position measurement using real-time ultrasound scanning; pain intensity measured with visual analog scale and function measured with the Anterior Knee Pain Scale. Results: The application of 3 sessions of DF significantly increased the patellar position at posttreatment evaluation (P < .001) and at 1-week follow-up (P < .001). There was not a significant difference on patellar position between posttreatment and follow-up measurements (P = .28). There were also a statistically significant decrease in pain and increase in function at posttreatment and at 1-week follow-up measurements (P < .001). Conclusion: This study found that patellar position, pain intensity, and function were significantly improved after 3 sessions of DF and at 1-week follow-up.