OBJECTIVE: To compare the efficacy and safety of two eccentric rehabilitation protocols for patients with symptomatic patellar tendinopathy. A new eccentric overload training device was compared with the present standard eccentric rehabilitation programme on a decline board. DESIGN: Prospective, randomised clinical trial. SETTING: Sports rehabilitation clinic, university sports laboratory, supplemented with home exercises. PATIENTS: 20 competitive and recreational athletes, all with clinical diagnosis of patellar tendinopathy, verified by MRI or ultrasound imaging. INTERVENTIONS: A 12-week rehabilitation period, either with bilateral eccentric overload strength training using the Bromsman device twice a week or with unilateral eccentric body load training using a decline board twice a week, supplemented with daily home exercises. OUTCOME MEASURES: The primary outcome was pain and function, assessed by the Swedish Victorian Institute of Sport Assessment for Patella (VISA-P) score. Secondary outcome measures were isokinetic muscle torque, dynamic function and muscle flexibility, as well as pain level estimations using visual analogue scale (VAS). Side effects were registered. RESULTS: Both treatment groups improved in the short term according to the VISA-P scores during the 12-week rehabilitation period. However, there were no significant differences between the groups in terms of pain and function. After a 3-month rehabilitation period, most patients could be regarded as improved enough to be able to return to training and sports. No serious side effects were detected in either group. CONCLUSION: In patients with patellar tendinopathy pain, two-legged eccentric overload training twice per week, using the new device (Bromsman), was as efficient and safe as the present standard daily eccentric one-legged rehabilitation-training regimen using a decline board.