Cassia fistula oil was investigated for antifungal activities against standard and clinical isolates of Candida species. Gas chromatography coupled with mass spectrometric (GC-MS) analysis of C. fistula oil revealed the presence of antimicrobial compounds like beta-sitosterol, stigmasterol, ergosterol, betulinic acid, lupeol, fucosterol, alpha-amyrin and friedelin. The minimum inhibitory concentration (MIC) of the pulp and seed oils ranged between 250-300 and 350-500 microg/mL respectively. Both oils also inhibited by>> or = 63.8% ergosterol bio-synthesis in Candida cell wall {fluconazole (standard)>> or = 89.1%)}. The MICs were significantly correlated with the ergosterol content decrease in the cell wall (Student's t test p < or = 0.005). We can, therefore, conclude that active compounds are present in Cassia fistula oil that primarily target ergosterol biosynthesis in Candida cell wall.