Rupture of ten major tendons occurred in 7 out of a total of 50 renal patients treated by chronic hemodialysis, in two renal units. The rupture occurred spontaneously without any special strain. Rupture was complete in five tendons and imcomplete in the other five. In 2 cases, rupture occurred simultaneously in both quadriceps tendons. In 1 case a single quadriceps and a triceps brachii tendon were affected together. In 3 cases one quadriceps tendon was affected and in the last case, one triceps brachii tendon alone was ruptured. All the patients suffered from long-standing renal disease with severe secondary hyperparathyroidism. We are anable to explain the high incidence (15%) of this complication in our area. No local factors were found in our study.