A total of 63 European hares have been collected from five Serbian agricultural regions. The hares assayed were divided into four age groups (3-6 months, 12 months, 12-24 months, and 24-36 months) and investigated upon presence at cadmium (Cd) and mercury (Hg) in the kidney and liver. The positive significant correlation (Ps-Pearson's coefficient) between Cd concentrations in the kidney and liver within age group the 3-6 months was found (Ps = 0.81, p < 0.001). Differences between Cd content in the kidney in comparison to liver were significant within all presented age groups (p < 0.001). Differences between recorded Hg levels in the kidney were not significant between presented age groups (p > 0.05). Statistically significant differences were registered between Hg content in the liver of the hares aged 24-36 and 12 months (p < 0.05). There were no statistically significant correlations registered between Hg concentrations in the kidney and liver within any particular age group (p > 0.05). The strong statistically significant associations were registered between Cd and Hg content in the liver (Cd L/Hg L) in the age group 3-6 and 12-24 months (Cd L/Hg L, Ps = 0.94; p < 0.001 and Ps = 0.91; p < 0.001, respectively). The polynomial regression model used for graphing the observed data seems to be a method for modeling the relationship between measured Cd and Hg concentrations in the liver and kidney as first approximation for bioaccumulation in hares.