This is a first description of a gynandromorph of an orchid bee, Euglossa iopoecila Dressier (Hymenoptera: Apidae: Euglossini). The specimen was collected at a chemical bait (eugenol) in an Atlantic Forest remnant in southern Brazil and shows a partial, bilateral asymmetry, with the right and left halves of the head displaying predominantly female and male characteristics, respectively. Except for the three left legs that show male morphology and a tuft of hairs detected only in the left side of second metasomal sternum (S2), the mesosoma and the metasoma exhibit female characteristics. The gynandromorph described here belongs to the mosaic or mixed category, because male and female characteristics are distributed patchily throughout the body of this individual. The main external morphological characteristics of the gynander are left and right antennae with 12 articles (like females), a mesosoma presenting a scutellar tuft (absent in males of this species), and a metasoma with six terga and six sterna that tapers to a point. Bilateral asymmetry in both metatibia is also noticeable: a normal corbicula is present in the right hind tibia, whereas the left hindleg brings a conspicuous deformation next to the tibial slit.