PURPOSE: The purpose of this study was to compare the clinical results between patellar resurfacing and patellar retention during total knee arthroplasties (TKA) in both sides of the knee from one patient. MATERIALS AND METHODS: A prospective randomized study was performed for 18 patients, who underwent only unilateral patellar resurfacing without any consideration for the condition of the patella cartilage, among the patients who had osteoarthritis and who underwent bilateral TKA from February 2004 to February 2008. The clinical results were compared using the American Knee Society clinical rating system, Feller's patellar score and the Kujala scoring system. RESULTS: The mean of the knee score and the function score were 94.3 and 73.7 postoperatively in the resurfaced patellar side and these values were 91.4 and 73.6, respectively, in the unresurfaced patella side (p=0.07, p=1.00). The Feller's patella scores were 26.5 and 25.3 for each side (p=0.219). The Kujala scores were 71.7 and 69.9, respectively (p=0.086). There was no statistically significant difference between both sides of the knee for all the parameters. CONCLUSION: There were no statistically significant differences between the resurfaced and non-resurfaced knees with comparing them according to the American Knee Society clinical rating system and the patellar evaluation systems. However, further studies are needed to observe whether these results are maintained in the long-term.