The aim of this study was to assess the Breastfeeding status among children aged 21 -27 moths. A cross sectional study was carried out in South Health Center (Tehran-Iran) in 2010. Four hundred 21 -27 month breastfed infants entered the study. This study compared some variables in 2 groups; weaning before and after 22 months. The level of significance was considered P < 0.05. Mean breastfeeding duration and median (either exclusive or combined) were 19.66 ± 6.40 and 22 months. Among all reasons were cited by mothers, some reasons like insufficient breast milk supply (77.9%), infant restless (77.1%), and Mother's reluctance (75.6%) were the most common causes of exclusive breastfeeding cessation. A significant relation was seen between breastfeeding duration and gestational age or birth trauma (P Value = 0.031, P Value = 0.04). Breastfeeding training and First mother-infant skin to skin contact had significant roles on breastfeeding duration (P Value < 0.05, P Value = 0.001, respectively). It seems lots of public health efforts and policy are needed to improve breastfeeding rate in our country.