Nanopolystyrene was used as a solid support for the covalent immobilization of Candida antarctica lipase B(Cal B) using the photoreactive reagent 1‐fluoro‐2‐nitro‐4‐azido benzene(FNAB) as a cou‐pling reagent. The obtained derivative was then used as a biocatalyst in a microwave assisted ester‐ification experiment. Factors such as contact time, pH, and enzyme concentration were investigated during immobilization. The hydrolytic activity, thermal, and operational stability of immobi‐lized‐Cal B were determined. The maximum immobilized yield(218 μg/mg support) obtained at pH 6.8 exhibited optimum hydrolytic activity(4.42 × 103 mU p‐nitrophenol/min). The thermal stability of Cal B improved significantly when it was immobilized at pH 10, however, the immobilized yield was very low(93.6 μg/mg support). The immobilized‐Cal B prepared at pH 6.8 and pH 10 retained 50% of its initial activity after incubation periods of 14 and 16 h, respectively, at 60 °C. The opera‐tional stability was investigated for the microwave assisted esterification of oleic acid with metha‐nol. Immobilized‐Cal B retained 50% of its initial activity after 15 batch cycles in the micro‐wave‐assisted esterification. The esterification time was notably reduced under microwave irradia‐tion. The combined use of a biocatalyst and microwave heating is thus an alternative total green synthesis process. Nanopolystyrene was used as a solid support for the covalent immobilization of Candida antarctica lipase B (Cal B) using the photoreactive reagent 1-fluoro-2-nitro-4-azido benzene (FNAB) as a cou-pling reagent. then used as a biocatalyst in a microwave assisted ester-notification experiment. Factors such as contact time, pH, and enzyme concentration were investigated during immobilization. The hydrolytic activity, thermal, and operational stability of immobi-lized-Cal B were determined. The thermal stability of Cal B improved significantly when it was immobilized at pH 10, however, the immobilized yield (218 μg / mg support) obtained at pH 6.8 exhibited optimum hydrolytic activity (4.42 × 10 3 mU p-nitrophenol / min) The immobilized-Cal B prepared at pH 6.8 and pH 10 retained 50% of its initial activity after incubation periods of 14 and 16 h, respectively, at 60 ° C. The yield was very low (93.6 μg / opera-tional stability was investigated for the microwave assisted esterification of oleic acid with metha-nol. Immobilized-Cal B retained 50% of its initial activity after 15 batch cycles in the micro-wave-assisted esterification. The esterification time was not properly reduced under microwave irradia- tion. The combined use of a biocatalyst and microwave heating is an alternative total green synthesis process.