Secondary School No. 31, located at 116 Lacul Tei Boulevard, Sector 2, Bucharest, is a public educational institution with a rich history dating back to 1924. Originally, the school's building comprised two separate wings: the "Girls' Primary School No. 36" facing Maica Domnului Street and the "Boys' Primary School No. 36" facing Dorin Pavel Street. In the 1948–1949 academic year, both units were transformed into 7-year schools, encompassing both primary and lower secondary education. Following the 1956 educational reform, the two units merged into a single entity named "Mixed School No. 31". 

Over the years, the school has undergone several modernization efforts. Although it had electric lighting from its inception, central heating was only introduced in the mid-1970s. In 1977, due to an increase in the student population, a new wing was added to the building, continuing the school's development.

Today, the school boasts modern facilities, including classrooms, laboratories for biology, physics, and chemistry, computer labs, a library, sports hall and field, dining hall, dormitory, medical and dental offices. The teaching staff is well-qualified, with many holding the highest professional degrees and actively participating in continuous professional development courses.

In the 2024 National Evaluation, students from Secondary School No. 31 achieved an average score of 6.37, with 73 graduates participating.