Background: This study aimed to determine the normal dimensions of the mitral annulus (MA) in Iranian population. Materials and Methods: This cross-sectional study was conducted using 88 fresh hearts of male and female cadavers for six months in Mashhad, Iran. Normal data were determined by measuring the exact dimensions of the MA in fresh hearts of patients who had died of non-cardiac causes and considering some parameters such as age, gender, stature, and weight. Images of the valves and leaflets were prepared by marking the anterior (A2, midpoint of anterior) and posterior areas of P1, P2, and P3 using a needle. To analyze the data, SPSS version 16 was used. Results: The means of anatomic area, anatomic perimeter, inter-commissural distance, A2-P1, A2-P2, A2-P3, Base-P1, Base-P2, Base-P3, and Base-A were 14± 1. 28, 8. 3± 1, 2. 7± 0. 42, 2. 27± 0. 37, 2. 3± 0. 43, 2. 06± 0. 35, 1. 66± 0. 43, 1. 2± 0. 97, 1. 5± 0. 66, and 3. 2± 0. 52, respectively. Comparison of the age groups regarding valve leaflets showed that Strut-P1 and Base-P2 were significantly different. Comparison of the valve leaflets and sub-valve indicators between the two genders reflected no significant differenc-es. Age groups differed significantly in terms of Strut-P1 and Base-P2 (P=0. 004 and P=00. 1, respectively). Conclusions: A2-P3, A2-P1, anatomic perimeter, and anatomic area were found to be related to gender. A2-P1 and A2-P2 and some leaflet indicators such as Strut-P1 and Base-P2 were associated with age, whereas Base-P2 was affected by body mass index.