It is not clear whether indicating TKA-surgery is advisable in depressed patients. A prospective cohort of 716 patients undergoing TKA was designed. SF36, KSS, WOMAC and VAS plus 2 satisfaction questions were evaluated. There were 2 groups: 200 patients were depressed and 516 were not. Preoperative/postoperative results show better scores for non-depressed patients on almost every sub-scale. Nevertheless, net change results (improvement) were quite similar: 65.74 improvement in depressed-KSS and 74.58 in non-depressed (P = 0.049); 8.93 net change in depressed-Physical Composite Score and 11.84 in non-depressed (P = 0.003); 2.38 in depressed-Mental Composite Score and −0.61 in non-depressed (P = 0.024). Depressed patients obtained great improvement from preoperative at one-year follow-up and even greater than non-depressed patients in some domains. Moreover, satisfaction was similar. Therefore, TKA can be recommended to depressed patients.