This paper explores the feasibility of converting waste fish scale into a high-performance,reusable, low-cost heterogeneous catalyst for synthesis of biodiesel from palm oil. The Infrared radiation(IR) and Gas chromatography-mass spectrometry (GC-MS) analysis revealed that a significant portion of the main component of fish scale i.e. HAP (hydroxyapatite) could be transformed into b-tri-calcium phosphate when calcined above 900 C for 2 h. methano/oil molar ratio 5:3 calcination temperature,900 C and amount catalyst 1 g oil corresponding to a maximum FAME yield of 72.64%. Reusability results confirmed that the prepared catalyst could be reemployed up to six times, procreating a potentially applicable avenue in biodiesel synthesis.