-The incidence of diploid males among 1457 individuals of different populations of six euglossine bee species (Eufriesea violacea , Eulaema cingulata , Euglossa annectans , Euglossa iopoecila , Euglossa pleosticta and Euglossa truncata ) was investigated with microsatellite markers. Bees were surveyed in Atlantic Forest fragments showing different sizes and degrees of human interference. Our analyses revealed that, although the frequencies of diploid males remained below 10 % for five out of six species studied, the frequencies of these males in three populations of Eg. annectans were above 15.0 %. For this species, while the average estimate of diploid males was around 11.0 %, the highest percentage (27 %) of such males was found for the population from an island. Our findings indicate that the frequency of diploid males can vary substantially among species and this fact should be taking into consideration in studies and conservation actions involving different euglossine bees. microsatellites / Euglossini / euglossine bees / Euglossa annectans / forest fragments