The Lequesne Algofunctional Index is a widespread international instrument and recommended by the World Health Organization (WHO) for outcome measurement in hip and knee diseases. Up to now there has been no German version of the questionnaire fulfilling the guidelines for cross-cultural adaptation and providing satisfactory metric quality. Based on these guidelines, we developed the German version of the Lequesne Algofunctional Index regarding osteoarthritis of the hip and knee joints presented in this article. All of the questions it contains have been worded as whole sentences, questions concerning walking performance have been substantiated by examples. In testing of the metric outcome (hip: n = 112; knee: n = 83), both questionnaires showed an excellent reliability (IKK > 0,88). As a validity criterion, the correlation with the WOMAC score was tested. We received a Spearman coefficient between 0,63 and 0,81, indicating a high correlation. Time needed to fill in the Lequesne score was 2 min. in patients, physicians took 1,2 min. to evaluate the questionnaire. Regarding the questionnaires handed back, the Lequesne score showed better results than the WOMAC index. Sensitivity, measured by the "standardized response mean", was good in both regions for the total score. Comparing the data received on pain-related questions, the WOMAC score however showed a better sensitivity. The German version of the Lequesne Algofunctional Index is a suitable outcome instrument to measure the intensity of pain, walking capacity and activity of daily life in patients with osteoarthritis of hip and knee joints.