Increasing incidence rate of breast cancer in young women obligates investigations of clinical and pathological features in this age group. Less hormone receptor expressions and more aggressive behavior has been discussed in very young breast cancer patients. In this study pathological data of patients diagnosed with Invasive ductal carcinoma referred to Shariati hospital and Tehran cancer institute between ۲۰۱۵ and ۲۰۱۸ was evaluated in two groups : under ۳۵ years old (Group۱) and above (Group۲). Each group contained ۱۵۶ cases. ۶۲.۸% and ۶۳.۵% Estrogen and Progesterone Receptor expressionwas reported in Group ۱ in comparison to ۷۷.۶% and ۷۴.۴% in Group ۲ ( P value= ۰.۰۰۴ and ۰.۰۰۳۸). Her۲ expression was found in ۴۱% and ۲۱.۲% in group ۱ and ۲ respectively ( P value= ۰.۰۰۰۱). There was ۴۱.۲ ± ۲۵.۲ and ۲۹.۶ ± ۲۱.۷ reported of Ki۶۷ in Group ۱ and ۲ ( P value= ۰.۰۰۱). In conclusion negative hormone receptor, positive Her۲ expression and higher proliferation rates is found in breast cancer patients under ۳۵-year-old