© Kamla-Raj 2015.As of the 2012-2013 academic year, the starting age for primary school has been changed to 66 months. The purpose of this research is to analyze whether basic concepts knowledge and academic development show any differences in children starting school at different ages. The group analyzed in this research consisted of 254 first-year students. The Bracken Basic Concept Scale and measuring tools for reading speed, reading comprehension and mathematical problem solving were used. It is observed that children show no significant difference in basic concepts at the beginning of the academic year, that the existing difference is on the concept of numbers, and that aside from the concept of letters there is no meaningful difference evidentat the end of the academic year. Students from the younger age group were able to learn to read. However, differences in the younger age group in reading comprehension and mathematical problem solving were observed.