Infection is the most serious post-operative complication of total knee arthroplasty. Its management is multidisciplinary and based on medical and surgical treatment. The aim of our work was to specify the epidemiological characteristics of these infections, as well as their bacteriological profile. We conducted a study involving 30 patients followed for infections on total knee prosthesis. The infections were classified as early, delayed and late. Our series included 22 women and 8 men. The average age was 63 years. The incidence of infection on total knee replacement was 3.3%. Initial arthroplasty was indicated for gonarthrosis in 23 patients and for rheumatic arthritis in 7 patients. There were 14 early, 13 delayed and 9 late infections.The most common organisms were staphylococci, isolated in 46% of cases, followed by gram-negative bacilli in 33% of infections and streptococci in 21%.