<p>Jelly palms (<i>Butia</i> spp.) are used by traditional communities and small farmers in subtropical South America. In the northern coast of Rio Grande do Sul, in Brazil, two species are used, <i>Butia odorata</i> and <i>Butia catarinensis</i>, both of which are threatened with extinction. Through interviews with roadside and shop sellers, we sought to assess the traditional knowledge associated with the use of genetic resources of jelly palms in that region. We also harvested local fruit samples for biometric analyses. The vendors confirmed that they sell fruits or other products of jelly palms, and that this activity is an important supplement to their income. They confirmed the absence of a commercial cooperative, and the interest in such an initiative. Most of the respondents perceive high variation in fruit size, especially among what they call different “types”, that is, the two species studied. High fruit size and shape variation were confirmed by our biometric analyses but these variables alone could not completely distinguish the two species. Our results showed significant engagement of the community of the North Coast of Rio Grande do Sul in using and selling jelly palms, but further attention from local authorities is necessary to promote their conservation and sustainable use.</p>