Background: Multiple percutaneous longitudinal tenotomies have been successfully undertaken in runners with isolated midportion Achilles tendinopathy (nodular lesions <2.5 cm) without any sign of paratendinopathy. Hypothesis: In the long term, minimally invasive multiple tenotomies allow the patient to remain involved in middle- and long-distance running. Clinical and ultrasound (US) evidence of paratendinopathy is a negative prognostic factor. Study Design: Case series study; Level of evidence, 4. Methods: A total of 39 patients were reviewed at an average follow-up of 17 years (range, 15-22 years) after US-guided multiple percutaneous longitudinal tenotomies for chronic Achilles tendinopathy. The Victorian Institute of Sports Assessment–Achilles (VISA-A) questionnaire was completed by each patient, maximum calf circumference and isometric plantarflexion strength of the gastrocsoleus complex were measured in both the affected and contralateral legs, and functional assessment was scored by the 4-point Boyden scale. Achilles tendon changes were also assessed according to the grayscale US grading system. Results: At the final follow-up, the maximum calf circumference and the strength in the operated leg were not significantly different than those measured preoperatively, but they were significantly lower than those on the contralateral side. This did not affect patients’ daily or sports activities. All patients had returned to their preinjury working occupation; 20 patients were still active in middle- and long-distance running, with an average current level of sport and function that was 60% ± 13% compared with baseline status (before onset of symptoms). Thirty of 39 patients (77%) reported good or excellent outcomes according to the Boyden assessment. On US assessment, the tendon was generally thicker than the contralateral asymptomatic tendon (average, 7.0 vs 8.7 mm, respectively; P = .003). There was no significant difference (P > .05) when comparing patients with good or excellent Boyden results versus those with fair or poor outcomes. The mean VISA-A score was 78.5, with no significant difference between patients with and without paratendinopathy on US assessment (P > .05). All of the patients who did not return to running or who gave up sports activities had signs of paratendinopathy. Conclusion: This approach to the management of midportion Achilles tendinopathy is safe, has a low cost, and is effective in the long term.