This survey explored the ethnobotanical uses of selected medicinal plants; Adiantum raddianum C. Presl. (Pteridaceae), Lippia alba (Mill.) N. E. Brown (Verbenaceae) and Coronopus didymus (L.) Sm. (Brassicaceae) used for respiratory diseases in Southern Santa Catarina (Brazil). This is timely as the incidence of respiratory disease is increasing in this state. Information was obtained through both interviews using a semi-structured questionnaire administered to 368 people and evaluation of published literature on these plants from scientific peer reviewed journals. The age profile of participants ranged from 20 to over 89 years, with females representing 75% of interviewees. Regarding their use of the medicinal species, 53% reported being users of one of the three plants. Approximately, 52% of users preferred to utilize L. alba, 40% C. didymus and 8% A. raddianum. The primary respiratory diseases reported for use by the plants included cough, flu or cold, lung disorders, bronchitis and asthma. There was also more scientific literature available to support the use of L. alba for treatment of respiratory diseases. This study contributes to the documentation of the medicinal and popular uses of L. alba, C. didymus and A. raddianum in Southern Brazil, in ways that respect and support their conservation. Further studies are warranted to evaluate the biochemical and pharmacological activities of C. didymus and A. raddianum.