ABSTRACT Zeolite-bacterial cellulose nanocomposite membrane (ZBCN) has been prepared and evaluated as a catalyst in the transesterification of waste cooking oil (WCO) to give biodiesel. Bacterial cellulose membrane was obtained during cultivation of Komagataeibacter as a bacterial isolate; meanwhile, zeolite A (ZA) was prepared from Egyptian ores. The results confirmed that, the amount of triglyceride (TG) converted into fatty acid methyl ester (FAME) was ≥77%, while the total conversion of TG and the conversion to other compounds were 84.4% and 7.4%, respectively, during 9 h and methanol to TG 40:1 molar ratio. XRD, SEM, EDX, and zeta potential measurements were utilized to characterize the prepared catalyst. TLC and HPTLC were employed to prove biodiesel successful synthesis and quantify its percentage in the product, respectively. The composition of FAMEs was determined by GC-MS. It revealed that the major components in the synthesized FAMEs were palmitic acid methyl ester (40.2%), oleic acid methyl ester (53%), and linoleic acid methyl ester (5.4%). The saponification number, iodine value, cetane number, and higher heating values of the synthesized biodiesel were 193.3 mg KOH/g, 54.6 g I/100 g, 62.26, and 42.3 MJ/kg, respectively, which meet the qualification of international standards. The acidity (1.68 mg KOH/g) and the viscosity (10 cSt) of the synthesized biodiesel by ZBCN showed superiority over their counterparts of WCO, but they still need further improvement.