In 1633 he joined the Dutch army where he worked in the headquarters in Maastricht. Subsequently he joined the Dominican Order where he adapted his first name Jean-Baptiste.
In 1640 he was sent as missionary to the Antilles from where he returned to France in 1658.
He is the author of several works about the Antilles where he described the indigenous peoples, the animals, and the plant world, including Histoire générale des îles Saint-Christophe, de la Guadeloupe, de la Martinique et autres de l'Amérique (Paris, 1654), Histoire naturelle et morale des îles Antilles de l'Amérique avec un vocabulaire caraïbe (1658), La Vie de Sainte Austreberte (1659) and l’Histoire générale des Antilles habitées par les Français (four volumes, 1667 – 1671). Particularly in has last work Du Tertre created the myth of the "Bon Sauvage" where he placed "the virtuousness of the heathencaribs above the immoral life of the Europeans"