To demonstrate the histomorphological structure of the dog lacrimal drainage system, 15 adult healthy dogs (Canis familiaris) were used. The lacrimal drainage passages composed of the excretory ducts, lacrimal punctua, canaliculi, lacrimal sac, nasolacrimal duct and the nasolacrimal ostium. The nasolacrimal duct was divided into three distinct parts; the caudal "Osseous", middle "membranous" and rostral "cartilagenous" parts. Microscopically, the lacrimal puncta and canaliculi were lined with stratified squamous epithelium which was keratinized in the puncta. The epithelium of the lacrimal sac as well as the caudal and middle portions of the nasolacrimal duct was pesudostratified columnar epithelium without goblet cells. The epithelium changed to be a stratified squamous in the rostral portion of the nasolacrimal duct and became keratinized in the nasolacrimal ostium. The scanning electron microscopy showed that, the main opening of the excretory lacrimal ducts appeared heart shaped, while the opening of puncta was ovoid shaped. The internal surface of the nasolacrimal duct was smooth and showed a few sporadic pores and clefts. The nasolacrimal opening was a flask shaped. The normal histomorphological structure of the dog lacrimal drainage system was very significant to identify and diagnose any disorders in these structures in the same species and in experimental studies for human being.