The acute effects of hyperglycemia in cognitive function and mood are not well elucidated. The aim of this study was to evaluate whether acute hyperglycemia alters the exploratory behavior of adult zebrafish. Fish were maintained aquariums containing 55 mM D-glucose solution for 14 days. Blood glucose levels and behavioral analysis were assessed before and after the D-glucose challenge. Immersion of adult zebrafish in a 55 mM D-glucose solution (14 days) increased blood glucose levels until the 14th day. There was no difference in weight gain between the two groups. Hyperglycemia did not induce anxiogenic or anxioly-tic behavior, nor did it alter the locomotor activity of the animals. We conclude that acute hyperglycemia does not alter the exploratory behavior of the adult zebrafish.