In this paper, the moment magnifiers that have been provided in the BS 8110 for the design of reinforced concrete short rectangular columns under biaxial bending was examined using a developed FORTRAN reliability-based program. First Order Reliability Method (FORM) was employed in the analysis. The reliability-based evaluation of the bending moment of coefficient () of 0.58 yielded satisfactory safety index of 2.74 under the ultimate loading and specified geometric properties. It was noted that a better safety index was achieved when the moment magnifier, characteristic concrete grade, diameter of steel reinforcement, concrete cover, and depth of column are systematically choosing through reliability-based analysis. It was found among the findings that there is an increase of safety index from 2.74 to 3.98 when the moment magnifier increases from 0.58 to 3.98 respectively for the same loading, materials and geometric properties of the column. It is therefore concluded that the reliability-based approach for the design of columns under biaxial bending moment is quite suitable.