A most efficient, safe and cost effective reagent for esterification of amino acids and carboxylic acids of aromatic and aliphatic by using NaHSO4 is discussed. This method is very much useful for aromatic carboxylic acids as well as aliphatic acids. Great advantage of this reagent is very safe in handling and it is not health hazard like HCl, H2SO4 and other acid catalyzed reactions. It is not expensive like other esterification reagents. Esterification reactions with NaHSO4 help in easy to isolation of the desired esters. Because of its low price, it reduces the cost of synthesis also.