In 1737, Serra became a priest, and three years later earned an ecclesiastical license to teach philosophy at the Convento de San Francisco. His philosophy course, including over 60 students, lasted three years. Among his students were fellow future missionaries Francisco Palóu and Juan Crespí. When the course ended in 1743, Serra told his students: "I desire nothing more from you than this, that when the news of my death shall have reached your ears, I ask you to say for the benefit of my soul: 'May he rest in peace.' Nor shall I omit to do the same for you so that all of us will attain the goal for which we have been created."