The ester, butyl caprylate has wide applications in commercial market and it also possesses characteristic fruity flavor. The work exhibits the effect of various reaction parameters and the optimization study for the synthesis of butyl caprylate in presence of bio-catalyst. To achieve maximum conversion theoptimum parameters thus established include; temperature 60 ◦C, mole ratio of caprylic acid and butanol as 1:2, lipase loading 2% (w/v), 250 rpm speed of agitation and 4g of molecular sieves. The immobilized enzyme wasalso recycled and reused for 7 cycles with only 30% loss from its initial activity. The thermodynamic parametersnat different temperatures were also determined. The esterification was conducted successfully with 92% as maximum conversion in 5 h in a stirred batch reactor under solvent free system and in presence of molecular sieves that was used to adsorb water formed in reaction.