Introduction. The aim of study was to analyze risk factors, mechanisms of injury, symptoms and time that elapsed from injury until operation of complete quadriceps tendon ruptures. Material and Methods. This retrospective multicenter study included 30 patients operated for this injury, of whom 28 (93.3%) were men. The average age was 53.7 years (18-73). Twenty-six patients had reconstruction of unilateral rupture and four of bilateral one. Results. Eighty percent of them had some risk factors for rupture of the tendon with degenerative changes. Eight patients had diabetes, seven patients were on renal dialysis, two patients had secondary hyperparathyroidism, five patients were obese and two patients had former knee operations. These injuries occurred in 80% following minor trauma caused by falls on stairs, on flat surfaces and squatting. The most frequent symptoms were: pain, swelling, lack of extension of knee and defect above patella, and three cases were initially misdiagnosed. During the first 10 days after injury, acute and chronic ruptures were reconstructed in 22 (73.3%) and 8 patients, respectively. Conclusion. Quadriceps tendon injuries most often happen to male patients with predisposing conditions in their fifth and sixth decade of life due to trivial trauma. Patients on renal dialysis are the most vulnerable population group.