The study aims to evaluate the degree of fat oxidation and the reuse of fried oils in fried meat and fish ball products sold in Ninh Kieu District, Can Tho City. The fat content was determined in fried products, as follows: fish balls (15 - 21%), beef balls (11 -14 %), and shrimp balls (15 - 23%). Because of the difference in the fat origin of the three types of fried products, the oxidation levels of these products are also different; therefore, this is possible through parameters related to the variation of fat such as acid index, peroxide index, malondialdehyde (MDA) content. The concentration of MDA was the highest in fried fish balls, and the lowest value was in beef balls. After surveying for five consecutive days, the highest concentration of MDA in fried products was obtained in the last days of the cycle (4th day). The acid value in the fried oil samples ranges from 0 - 1 mg, the peroxide index from 2 - 5.78 meq/kg, and the concentration of MDA ranges from 0.22 - 2.98 µmol/L. A combination of results of the degree of fat oxidation in fried meat and fish ball products and frying oils indicates that the sellers reused the oils and tended to renew them every 3 - 4 days.