Behavioral literature is examined tor information that could clarify the manner in which rodent behavior is mediated by olfaction. Functional use of olfaction is readily apparent in some of the behaviors reviewed, for example, bait shyness, olfactorally modulated aggression, olfactory marking of and recognition of stressful environments, and inhibition of food seeking by odors generated from frustration. Other behaviors are reviewed in which olfaction is thought to play an important, though yet undelineated role, for example, differences in approach preference based on sexual dimensions. Still other olfactory-associated behaviors are reviewed which meet current standards of inferential significance yet lack any apparent function for the animal. It is concluded that a coherent understanding of the functional use of olfaction by rodents awaits a shift in the philosophy of research away from rigorous examination of loosely selected odorants and behavioral measures toward rigorous examination of normal behaviors in natural social contexts.