The objective of this study was to explore the histomorphometric investigation in the mammary gland of indigenous sheep breed “Madras Red”. The present study was conducted in adult lactating and non-lactating (n =6 each) Madras Red ewes. The mammary gland in ewes was a compound tubulo-alveolar gland surrounded by a connective tissue capsule. The alveoli were the principal secretory unit lined by simple cuboidal epithelium. Well-developed alveoli, filled with secretions and lipid droplets were observed in lactating animals. The non-lactating alveoli contained obliterated lumen without lipid droplets. The connective tissue stroma was well developed in non-lactating animals. Alveolar and intralobular ducts were lined by simple cuboidal epithelium. Interlobular and large lactiferous ducts were lined by bilayered cuboidal epithelium. Significant difference was observed in the length of lobule, breadth of lobule, number of alveoli per lobule, alveoli size, alveolar luminal diameter, nucleus diameter, thickness of interalveolar septa and thickness of interlobular septa.