BACKGROUND Revision total knee arthroplasty (TKA) is one of the most demanding as well as increasing orthopaedic operations. The influence of a higher body weight or body mass index (BMI) on the results of revision TKA is not evident so far. We therefore hypothesised that obesity as well as a high body weight could influence the results of revision TKA. METHODS 75 consecutive revision TKA in 75 patients were included and stratified according to a BMI greater or smaller than 30 kg/m2 and a body weight greater or smaller than 90 kg. The Knee Society score (KSS), the function and the knee subscales were analysed pre- and postoperatively as well as the pre- to postoperative improvement. The duration of the procedure, the occurrence of complications, the blood loss and the length of hospital stay were collected. RESULTS All patients showed a significant improvement of the KSS and function score (p < 0.05). There was a tendency to superior results in patients with a smaller BMI and a lower body weight. This tendency was most pronounced in the function subscale which depicted significant differences in favour of a BMI smaller 30 kg/m2. No significant differences were observed in the other analysed factors. CONCLUSIONS BMI greater than 30 kg/m2 as well as a higher body weight seem to negatively influence the function of revision TKA. However, all patients significantly improved after revision TKA and no differences were found according to the occurrence of complications. Therefore, revision TKA should not be refused to obese or heavy patients.