Background: Medicinal plants represent the oldest form used by humanity in the prevention and/or cure of their illnesses. They have low cost, are culturally widespread and can be cultivated in backyards.Methods: The objective was to know which medicinal plants are used and grown in homegardens, as well as their indication and the parts used by the residents of Lagoa da Prata Community, in the municipality of Parnaiba, Piaui. 174 people were interviewed, a total of 91 homegardens. Data were collected for direct data collection, structured interview, guided tours, photographic records, interview recordings, field journal annotations, Value of Use (VU) and Relative Importance (RI). Results:The survey recorded 30 plants, distributed in 19 families. The species with higher VU were Gossypium hirsutum L. (1.28), Dysphania ambrosioides (L.) Mosyakin & Clemants (1.12) and Ocimum gratissimum L. (1.12).Conclusions: Using such methods it was observed that the interviewees cultivated a variety of plant species used to treat a large number of diseases.