In the present study, the feasibility of utilizing Musa spp "Pisang Awak" peduncle derived ash as a highly effective renewable heterogeneous basic catalyst for transesterification of underutilized non-edible Ceiba pentandra oil (CPO) was investigated. The physiochemical characteristics of the calcined banana peduncle (CBP) were studied by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy and Energy Dispersive Atomic X-ray spectroscopy (SEM-EDAX). Biodiesel was produced by a two-step esterification-transesterification process. In the first step, FFA content of the oil was reduced from 7% to 1.6% using reaction conditions of 1.0 vol% H2SO4 concentration, 1 h reaction time, 1:4 v/v methanol to oil volumetric ratio with constant reaction temperature of 60 degrees C. In the second step, response surface methodology (RSM) using central composite design (CCD) was employed to determine the optimal process conditions of transesterification process variables. Based on the RSM results, the optimum process conditions for transesterification of CPO into fatty acid methyl ester (FAME) was found to be 1.978 wt% catalyst concentration, 60 min reaction time, 9.20:1 methanol to oil molar ratio with a maximum predicted FAME yield of 99.36% which was evaluated experimentally as 98.69 +/- 0.18%. (C) 2019 Elsevier Ltd. All rights reserved.