The International Junior Science Olympiad (or just IJSO) is a major international academically competition held annually and the only international academicals competition that covers physics, chemistry and biology at the same time. The competition is known for its intricacy as it requires a wide knowledge range in all three sciences. Top students from each country are selected to the competition and each get a chance to compete with their counterparts from across the globe.

For the competition, each country may only send a team of up to 6 students, 15 or younger, and 3 official team leaders.

The examinations consist of three separated tests, done in different days. The tests require knowledge about science of physics, chemistry and biology. The maximum score is 100 points.

• Stage 1 - Usually, 1st round of the written exam is conducted in the month of November every year.
• Stage 2 – 2nd round is conducted usually in the month of February every year.
• Stage 3 – 3rd round is conducted in the month of April to June every year.

The top 10% students receive gold medals, the next 20% students receive silver medals and another 30% receive bronze medals.

Also, team prizes are offered to the best results at the experimental examination and the best country in the tournament. Individual prizes are offered to the best student in the theoretical examination and to the best overall. The Local Organizing Committee (LOC) is responsible for giving official participation certificates to all students, leaders and observers.