This study demonstrates the histological and histochemical structure of the albino rat seminal vesicles at different post-natal ages and in old age. The seminal vesicle of newly born albino rat was represent ed by a simple tube lined with pseudostratified columnar epithelium and surrounded with mesenchymal tissue. At 10 days, the seminal vesicle became sacculated with the appearance of simple folds in their mucosa and the mesenchymal tissue became differentiated into a muscle layer and a connective tisue layer. The epithelium changed gradually into simple columnar (secretory type). The onset of secretion began at one month of the post-natal life. The seminal vesicle of adults was differentiated into proximal and distal p < strong>arts with distinct histological and histochemical differences. In old age, signs of decreas ed activity was observed both in the histological structure and histo chemical characteristics of both parts of the gland. These points, were discussed in the light of the available literature.