Purpose Studies have shown that up to 25 % of TKA patients are dissatisfied with the implanted knee, even if registry data shows ten-year revision rates below 5 %. It has been the question of our study, if it would be possible to identify those patients at risk for dissatisfaction pre-operatively. Methods The data of 1,121 consecutive TKA patients with a follow-up between one and six years have been analysed retrospectively. Demographic, radiologic and perioperative variables have been recorded and all patients were asked by questionnaire for satisfaction with the implanted knee. Logistic regression models have been used to identify significant risk factors. Results The data of 996 patients (89 %) were complete, 849 (85.2 %) reported satisfaction and 147 (14.8 %) dissatisfaction. Patients' satisfaction was independent of the time after operation (p=0.285). The only factor which influenced patients' satisfaction was the osteoarthritic severity. In comparison to severe arthritis Kellgren Lawrence IV°, the risk for dissatisfaction was 2.556-fold elevated for arthritis grade III°(p<0.001) and 2.956-fold higher for grade II°(p=0.001). Conclusions Patients suffering from mild or moderate osteoarthritis are at risk for dissatisfaction after TKA. The TKA indication in those patients should therefore be critically proven. Furthermore, to adjust patients' expectations, the elevated dissatisfaction risk in case of mild or moderate osteoarthritis should be included into patients' pre-operative information.