We aimed to evaluate the possibility of hamstring tendon contamination, the correlation with clinical infection and its association with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values in 89 anterior cruciate ligament reconstructions. Two tissue samples were obtained for culture from each graft: immediately after harvesting the graft and before implantation. The ESR and the CRP were evaluated preoperatively and on the 4th and 20th postoperative days. Nine patients (10%) had positive cultures but no patient had signs of postoperative infection. All patients had ESR and CRP values elevated at the 4th postoperative day. ESR and CRP values returned to normal levels at the 20th postoperative day. Higher mean values of CRP levels at the 4th day were observed in patients with contaminated grafts compared to those with uncontaminated. Both values reached normal levels at the 20th postoperative day.