A new case of gynandromorphism in bees is described and illustrated for the first time for Xylocopa (Neoxylocopa) frontalis (Olivier), a widely distributed carpenter bee in the neotropical region. The mixed gynandromorph, recorded from a single specimen from Paraguay, exhibits a mixture of male and female features in all tagmata. Previous literature records of gynandromorphs in Xylocopa Latreille are summarized, and the species identity of some gynandromorphs recorded for South America is revised. Including the specimen described herein, gynandromorphs are now known for a total of 12 species in Xylocopa, half of them in the neotropical subgenus Neoxylocopa.