22 PubMed articles in English were identified using the key words: 'risk factors', 'infection', and 'primary total knee arthroplasty (TKA)'. The 10 most relevant articles were reviewed. In one study, obesity and diabetes were considered risk factors for infection following TKA. In another study, postoperative infection correlated with a history of open reduction and internal fixation, male gender, remnants of previous internal fixation material, and body mass index. In yet another study, the risk factors were (in decreasing order of significance): congestive heart failure, chronic pulmonary disease, preoperative anaemia, diabetes, depression, renal disease, pulmonary circulation disorders, obesity, rheumatologic disease, psychoses, metastatic tumour, peripheral vascular disease, and valvular disease.