In this research, bamboo leaf ash was utilized as ZrO2 support for heterogeneous catalyst application. The preparation of ZrO2-supported bamboo leaf ash (ZrO2/BLA) was conducted by the impregnation method with a metal content of 20%wt. The physicochemical characterization of the prepared material was studied using XRD, gas sorption analysis, FTIR and SEM-EDX. The material was tested for use in the biodiesel conversion of soybean oil under microwave-assisted conversion. The results show that the physicochemical characteristics of ZrO2/BLA facilitated the catalytic activity in biodiesel conversion. The effects of the reaction method, the methanol-to-oil molar ratio, and the catalyst weight were investigated. The microwave-assisted method gave yields comparable to those obtained via the reflux method in less time. The optimized conditions of fatty acid methyl ester (FAME) production using the microwave-assisted reaction method were a 15:1 methanol-to-oil molar ratio, 30 min of reaction time and 12%wt. catalyst weight. The catalyst exhibited reusability properties, as indicated by its relatively similar yields, initial rates and turnover frequencies observed when fresh and reused catalysts were used.