Folk medicinal practitioners play an important role in the primary health-care system of a substantial segment of the rural and urban population of Bangladesh. For hundreds of years, the population of Bangladesh has mainly relied on traditional medicinal practitioners known locally as “Kavirajes” or “Vaidyas” for the treatment of various ailments. The mainstay of their formulation is medicinal plants, which is either administered orally or topically in the form of decoction, paste, pill, juice, or direct administration of the whole plant or plant part. The objective of this survey was to find out about medicinal plants used by the folk medicinal practitioners (Kavirajes) of Jhenaigati Upazila to treat various ailments. Detailed information was collected from Kavirajes about plants, plant parts or combination of plants used, formulation of medicines, dosages as well as ailments for which the plants are used. Plant specimens were collected and dried on the field and later brought back and identified at the Bangladesh National Herbarium. It was observed that the Kavirajes used more than 140 plants. These plants were distributed into 65 families. The Fabaceae family provided the largest number of species (8) followed by both Cucurbitaceae (7) and Apocynaceae (7) families. The Myrtaceae, Apiaceae, Lamiaceae, Arecaceae, Asteraceae, Moraceae and Liliaceae families provided 4 plants each. The Combretaceae, Piperaceae, Araceae, Malvaceae, Acanthaceae families provided 3 plants each. The Anacardiaceae, Lythraceae, Lauraceae, Solanaceae, Asparagaceae, Zingiberaceae, Poaceae, Annonaceae, Phyllanthaceae, Rosaceae, Boraginaceae families provided 2 plants each. The rest of the families contain single plant. Leaf formed the most frequently used part (51.16%), followed by fruit (36.43%), root (30.23%), bark (22.48%), seed (20.93%), flower (13.95%), and stem (11.62%). The percentage of whole plant used in treatment is 13.95%. Sixty-two plants were shown to have beneficial effects in the treatment of gastrointestinal problems including diarrhea, dysentery, constipation, loss of appetite, and acidity etc. Forty-four plants were effective in the treatment of respiratory illness like asthma, coughs, and colds. Thirty-one plants were found to inhibit adverse inflammatory reactions. Twenty plants have beneficial effects on diabetes treatment. Almost eighteen plants have the potential to treat kidney and urinary tract disorders. Thirteen plants were used to treat jaundice and poisonous stings including snake bite, insect bite and scorpion stings. Nine plants have been found to treat eye problems including infections, sore eyes, eye pain etc. Eight plants were found to be useful in the treatment of mental complications. Additionally, many of these plants were used also to treat worm, infection, infertility, gout, malaria, skin problem, abdominal pain, allergy, cancers, dementia, dyspepsia, cut, burn, menstrual problems, sexual disorders, bleeding from cuts and wounds, helminthiasis, leprosy, vomiting, hypertension, heart disorders, tumors, rheumatism etc. The medicinal plants used by the Kavirajes can form a rich source of plants for further scientific studies leading to discovery of novel therapeutic compounds.