||This thesis aims to assess the technical efficiency of grammar schools in the Czech Republic. We analyze a sample of 263 grammar schools (out of 362) and use data of cohort that graduated in 2012. We adopt a two-stage approach to efficiency analysis. In the first stage, efficiency scores are obtained through the data envelopment analysis under different returns to scale assumptions. The average efficiency of Czech grammar schools is 92% if variable returns to scale are considered. In the second stage, the efficiency is related to school and environmental characteristics using a Tobit regression. Our results suggest that the percentage of female students has a positive effect on efficiency as well as the school size and the share of students attending the 6 or 8 year study program. On the contrary, schools offering a vocational program along with a grammar school program are found to be less efficient. We have not found evidence that the share of not qualified teachers, yearly salary per teacher, state/private status, size of the town in which a school is located or any other environmental variable affect efficiency.