Cactaceae is one of the most threatened plant families, in part as a result of the illegal extraction of plants for ornamental use. However, reports of the seizure and reintroduction of cacti are scarce and do not include species of Melocactus, the genus of Cactaceae in Brazil that has the highest number of threatened species. The coroa-de-frade Melocactus violaceus is endemic to Brazil and categorized as Vulnerable on the IUCN Red List. We report the seizure of 37 individuals of coroa-de-frade extracted illegally from their natural habitat, the results of their reintroduction to Paulo César Vinha State Park, in Espírito Santo state, Brazil, and provide information for environmental monitoring agencies regarding how to proceed in seizure cases, with the goal of minimizing the impacts of this illegal practice on the species. After seizure, 25 individuals were cultivated in a greenhouse and 12 were reintroduced in restinga, the natural area of occurrence of the species. After 6 months, survival was 76% for those individuals cultivated in the greenhouse and 84% for those planted in restinga, showing that rapid reintroduction of species with ornamental appeal, preferentially in their natural habitat, can reduce the impacts of illegal extraction. This reintroduction protocol can be used by managers of conservation units, contributing to the maintenance of threatened cactus species in their natural habitat. [ABSTRACT FROM AUTHOR]