Dopamine, one of the biogenic amines, plays multiple regulatory roles in reproduction and behavior in social insects and can act as a neurotransmitter, a neuromodulator, and as a neurohormone. Dopamine is predominantly synthesized in the central nervous systems (CNS) from tyrosine via DOPA and is inactivated by conversion to a number of metabolites. Quantitative analyses of dopamine and its precursors and metabolites cast light on the role of dopamine in the regulation of behavioral and/or physiological changes. The genes encoding dopamine receptors and transporters were recently characterized in honeybee and their patterns of expression in different behavioral or reproductive states have been investigated. These analyses have helped to elucidate the signaling pathways and target cells involved. In eusocial Hymenoptera, dopamine accelerates reproduction, most prominently ovarian development and mating flight behavior. These functions are conserved in solitary insects, but their regulatory systems of brain dopamine appear to be different from those operating in highly eusocial species such as the honeybee females. Dopamine also modulates locomotor activities and associative learning. These behavioral modulations are likely to contribute to behavioral specialization accompanying division of labor in a colony.