Author's Abstract. Eucalyptus comprises the largest planted area of cultivated production forest in Brazil. Genetic modification (GM) of eucalyptus can provide additional characteristics for increasing productivity and protecting wood yield, as well as potentially altering fiber for a diversity of industrial uses. However, prior to releasing a new GM plant, risk assessments studies with non-target organisms must be undertaken. Bees are prominent biological models since they play an important role in varied ecosystems, including for Eucalyptus pollination. The main goal of this study was to evaluate whether a novel event (Eucalyptus 751K032), which carries the cp4-epsps gene that encodes the protein CP4-EPSPS and nptII gene that encodes the protein NPTII, might adversely affect honey bees (Apis mellifera) and stingless bees (Scaptotrigona bipunctata). The experiments were performed in southern Brazil, as follows: (i) larvae and adults were separately investigated, (ii) three or four different pollen diets were offered to bees, depending on larval or adult status, and (iii) two biological attributes, i.e., survivorship of larvae and adults and food intake by adults were evaluated. The diets were prepared with pollen from GM Eucalyptus 751K032; pollen from conventional Eucalyptus clone FGN-K, multifloral pollen or pure larval food. The insecticide dimethoate was used to evaluate the sensitivity of bees to toxic substances. Datasets were analyzed with Chi-square test, survival curves and repeated measures ANOVA. Results indicated no evidence of adverse effects of Eucalyptus pollen 751K032 on either honey bees or stingless bees assessed here. Therefore, the main findings suggest that the novel event may be considered harmless to these organisms since neither survivorship nor food consumption by bees were affected by it.