Polyphenoloxidase (PPO) was isolated from starfruit (Averrhoa carambola, L.) and purified by acetone precipitation and dialysis. The optimum pH for the acetone purified PPO catalysed oxidation of catechol was found to be pH 7.2 Heat inactivation studies showed that the enzyme was heat-labile. Half-lives for PPO inactivation at 70 °C and 75°C were found to be 4.6 min and 3.1 min respectively. The Michaelis constant (K m) and V max for catechol with PPO was 0.061M and 20 U'ml-2 respectively.