-A large number of studies suggest a close relationship between olfactory and affective information processing. Olfactory bulbectomized rats are used for establishing a model for depression and exploring dysfunctions in many physiological systems. Some depressed mothers may experience problems in breastfeeding, such as insufficient amount of milk production and discontinuation. Despite available studies dealing with relationship between depression and breast-feeding difficulties, the effect of depression on lactation through alterations in mammary gland structure is largely unknown. In this study, olfactory bulbectomized rats were used to determine whether depression affects mammary gland tissue. Experimental groups consisted of 3 parent stocks, each containing 5 male and 10 female adult rats. Prior to breeding period (10 week), females in each group were designed as 1) control, 2) sham-operated, and 3) bilaterally bulbectomized. After breeding period, males were removed from cages. Animals were monitored during pregnancy. Each female rat was then housed in individual cages with own offsprings after parturition and monitored for 4 weeks of lactation. At the end of the experiment, dams were decapitated for brain and mammary gland examinations. The number of parturition was 8, 6, and 5 and mean of litter was 6±2, 5±2, and 4±2 in control, sham, and bulbectomized groups, respectively. The frequency of bulbectomized rats exhibiting aggressive and non-nursing behaviors was greater than the other groups, with as higher litter mortality rate. Moreover, body weight and breast mass decreased in bulbectomized rats as compared to rats in other groups. Neurodegeneration in hippocampus, habenula, basal ganglia, salivatory nuclei, and autonomous ganglia of glands were present in bulbectomized rats. Decreased number and size in tubuloalveoalar compartments scattered obliterated lactiferous ducts were detected in mammary glands of bulbectomized rats. Data suggest that olfactory bulbectomy adversely affect reproductive and lactational status, perhaps through dysfunction of stimulus system among olfaction-brainendocrine- secretion-limbic and reproductive organ feedback loops. In patients with depression, impaired signaling between brain andmammary glandmay lead to alteration of mammary gland structure and consequently lower lactation performance.