A numerical study was performed to provide information about the temperature distribution of three dimensional cylindrical fin in steady state and homogeneous material properties. A brief literature review shows that much of work on fins has been carried out analytically and numerically in one dimensional and two dimensional conditions. This study is concerned about the three dimensional temperature distributions on a cylindrical fin, optimum dimensions and heat transfer from the fin, the fin efficiency and fin effectiveness of the cylindrical fin when fin base was maintained at a constant temperature. The necessary equations are solved by finite difference method and iteration method using FORTRAN code. The whole investigation was done using different material and different dimensional fins to find out the optimum effectiveness and efficiency for predefined condition.