Context - The incidence of tendon injuries and tendinopathy has risen substantially in the past decades.Objective - To assess the noninferiority of therapy based on the homeopathic preparation Traumeel S ointment (Heel GmbH, Baden-Baden, Germany) compared with treatment based on diclofenac 1% gel in patients with tendinopathies of varying etiology.Design - Nonrandomized, observational study.Setting - Ninety-five homeopathy and conventional medical practices in Germany.Patients - Three hundred fifty-seven patients aged 18 to 93 years with tendinopathy of varying etiology based on excessive tendon load rather than inflammation.Interventions - Traumeel S ointment or diclofenac 1% gel for a maximum of 28 days.Main Outcome Measures - Efficacy was measured on a four-degree scale on pain-related variables, on variables related to motility, and on overall treatment outcome. Tolerability was monitored as adverse events. Compliance was assessed by practitioner and patient on a four-degree scale.Results - The patients groups were comparable at baseline. The changes in summary score of all pain-related variables were −5.3 ± 2.7 (all values means ± SD) in the Traumeel group and −5.0 ± 2.7 in the control group. Changes for all motility-related variables were −4.2 ± 3.8 with Traumeel and −3.7 ± 3.4 with control therapy. The summary scores for all clinical variables were reduced by −9.5 ± 5.7 with Traumeel therapy and by −8.7 ± 5.4 with diclofenac-based treatment. Homeopathic therapy was noninferior to diclofenac therapy on all variables. For motility-related variables, there was a trend toward superiority of Traumeel. Treatments were well tolerated with no treatment-related adverse events.Conclusions - The results suggest that Traumeel ointment is an effective alternative to nonsteroidal antiinflammatory drugs therapy for the acute symptomatic treatment of patients with tendinopathy.