Background: In human, mast cells (MCs) are classified according to their proteases' content into tryptase-containing mast cells (MCT) and tryptase and chymase-containing mast cells (MCTC). In addition to phenotypic differences in MC subtypes, there is also functional distributional heterogeneity. The present study was carried out to determine the physiological distribution of mast cells in the different components of human ovary of different age groups. Mast cell sorting according to their proteases content was also attempted with special emphasis on the possible mechanism of their effects on ovarian functions. Material and methods: Archival blocks of human ovarian tissue from females with age ranging from 16 to 75 years were used. The specimens were divided into reproductive- and postmenopausal-age groups. Histological study using haematoxylin and eosin as well as Masson trichrome staining was performed. Immunostaining using monoclonal antibodies against tryptase and chymase was also carried out. Morphometric measurements in the form of mast cell count per high power field as well as optical density of positively immuno-stained mast cells in addition to measurement of area and area per cent were done. Obtained data were statistically analyzed for significance using student's T- test. Results: MCs were mainly found in the deep cortical stroma and in the vicinity of blood vessels. Occasionally, few cells were found in the corpora lutea. There were no immunostained MCs in the walls of the different ovarian follicles, corpora albicans or in the periphery of the ovarian cortical stroma. Statistical analysis revealed that the number of MCT was significantly higher than MCTC in the reproductive-age group in comparison to the postmenopausal-age group. The postmenopausal-age group demonstrated the presence of statistically significant more degranulated MCTC and high collagen content in comparison to the reproductive-age group. Conclusion: MC subtypes follow specific distribution pattern within the ovarian tissue in the different age groups which has an impact on different ovarian functions in many physiological and pathological situations.