Introduction: Family size is an important population, socio-economic and reproductive health issue. Number of children preferred in a society generally influences the population of society and population growth rate. Education of both the parents play a significant role in determining the family size. The study aims towards finding the effect of education of parents on the family size, so that using local data, attention can be drawn on this major demographic determinant to improve the quality of life of people. The study was conducted in Khyber Teaching Hospital MTI Peshawar. The duration of our study was from July 2020 to August 2020.Our sample was of 100 married couples. Methodology: After taking informed consent from the respondents, data was collected through a preformed questionnaire having two separate sections. Section 1 included the demographic details of the respondents while section 2 was based on a total of 14 close ended questions regarding the number of children, educational status, family values and their personal awareness about contraceptives and education. Results: According to our research study conducted on a 100 people, in which age distribution of male respondents showed that 29% of them are in the age of 40-49 years (period of reproductive potential).63% of them were qualified up to graduate and post-graduate level. Age distribution of female respondents showed that most of them were between ages of 30-39 years (period of high reproductive potential).66% of them were qualified up to graduate and post graduate level. Chi-square valued showed that association between the education level of parents and number of children with the p-value of <0.001 for males and <0.005 for females.63% of highly educated families have less children while less educated have more children showing a negative relation between parent education and family size. Conclusions: Level of education has direct relationship with the use of contraceptives and inverse relationship with the number of children. Education process helps parents by raising awareness and decision making about the use of contraceptives and ultimately family size. Keywords: Parent Education, Contraceptives, Family size.