Background and Objective: Even if RATKA (Robotic assisted total knee arthroplasty) is a widely used surgery, there is still a gap of knowledge about patient reported outcomes. The aim of this study was to compare self-reported outcomes in patients who underwent RATKA (with ROSA - “RObotic Surgical Assistant system”- technique) and patients who underwent the manual surgery (traditional technique). Methods: We compared 73 patients operated with ROSA technique with 62 operated with traditional technique. The data were collected with WOMAC (Western Ontario and McMaster University Osteoarthritis index), a self- administrated questionnaire that investigates pain, stiffness, and functionality of the patients. We performed two surveys, the first was before the intervention and the second was 6 months after the surgery. We evaluated the absolute and percentage differences between the two groups. Statistical analysis were performed with two-tailed T-test and chi-squared test. Results: After the 6 months follow-up, we observed lower PROM scores in both groups. In particular, the total WOMAC score in the ROSA group dropped from 66.0 to 32.5, while in the other group it decreased from 62.4 to 24.6. The post-operative absolute difference between the WOMAC scores of two groups was 7.9 points (95%CI: -12.49 to -3.23) in favor of conventional technique. On the other hand, the analysis of the percent improvement, despite still slightly in favor of the conventional group (54.1% vs 47.8%), failed to reach statistical significance (p=0.23). The post-operative percentage difference was 6.3% (95%CI: -4.0% to 16.7%). Conclusions: These findings indicate that a clear superiority of RATKA to conventional TKA is not yet demonstrated. Moreover, a knowledge gap about the proper methodology to analyze the patient reported outcome measures may exist. Also, given the recent evolution of the technology, an urgent need to conduct studies with longer term outcome evaluation is compelling.