We developed a method to measure wound temperature during phacoemulsification with a thermometer and compared the temperature between pulse and nonpulse modes. In cases with partial or complete obstruction of the aspiration port, wound temperature was significantly lower in the pulse mode versus the nonpulse mode. It was ascertained that pulse mode phacoemulsification prevents thermal burn of the wound in the hard nucleus during cataract surgery. This method is useful to evaluate wound temperature during phacoemulsification under various conditions.