ObjectiveTo evaluate the contamination rate of hamstring tendon autograft by comparing two different techniques, and to verify whether intraoperative contamination is associated with clinical infection development in patients submitted to reconstruction of the anterior cruciate ligament. MethodsOne hundred and ten hamstring tendons autograft anterior cruciate ligament reconstructions were performed and divided into two groups: 1 – hamstring tendon retraction technique and 2 ‐ technique maintaining the tibial insertion of the hamstring tendon. During the preparation, two grafts fragments were sent for culturing; the harvesting time, preparation time, and total surgery time were measured. Twenty‐four hours after the surgery, the C‐reactive protein was assayed. Clinical outpatient follow‐up was performed up to 180 days postoperatively. ResultsAlthough there were two postoperative infections, there was no graft contamination or difference between the groups in relation to the graft preparation time and the 24‐hour post‐operative C‐reactive protein. The classic technique presented longer graft harvesting time (p = 0.038) and there was no statistical difference between the two groups regarding the degree of contamination and consequent clinical infection, although two patients in group 2 had infection with negative perioperative cultures. ConclusionBased on the results obtained, there was no association between graft contamination and the time or technique of its preparation. In addition, there was also no association between intraoperative contamination and development of clinical infection, nor was there any sign of an association between the early alteration of C‐reactive protein and the onset of infection.