The Tonchongyas are a small tribal community who can be found in scattered localities in the various districts of Chittagong Hill Tracts in the southeastern part of Bangladesh. Very little is known about the tribal medicinal practices of this tribe. The objective of the present study was to document the medicinal plants used by a Tonchongya tribal healer (TTH) practicing in Rangamati district in the Chittagong Hill Tracts. Interviews of the TTH were carried out with the help of a semi-structured questionnaire and the guided field-walk method. The TTH was observed to use a total of 13 plants in his formulations of which 12 could be identified. These plants were distributed into 8 families with the Fabaceae family contributing the maximum number of species. The plants were used by the TTH to treat a wide variety of ailments, which included gastrointestinal disorders, cancer, pain, enlargement of spleen, sinking of voice, physical weakness, biliary disorders, piles, leucorrhea, urinary disorders, menstrual problems, poisoning, fever, helminthiasis and skin disorders. The use of different parts of the same plant to treat different ailments suggests that the TTH possessed quite extensive knowledge on the medicinal properties of the plants that he used. As such, the plants merit scientific attention for further research leading to possible drug discoveries.