„Olimpíada Brasileira de Biologia“

  • Established since: 2005
  • Website: Official website
  • Website language: Portuguese (Brazil)

Contact data

Country coordinator

Ph.D. Sonia Aparecida de Andrade Chudzinski

Hosting institution

Instituto Butantan
Avenida Vital Brasil, 1500
05503900, Sao Paulo
Sao Paulo, Brazil


Appointing institution

Instituto Butantan

Avenida Vital Brasil, 1500

05503900 Sao Paulo, Sao Paulo, Brazil


Organization & structure

Typically, we apply three rounds of examinations selecting our Olympic delegation. The first round takes place in the registered schools and is applied by the high-school teachers. The first test has 30 multiple choice questions and has only eliminatory character. The first phase usually occurs in late March.

After the registration of students in our online system, short listing the selected students for the second phase is done. Our guidelines state that approximately 5% of the best students are qualified for the second phase of the OBB.

The second round contains 100 multiple choice questions and is applied by state coordinators throughout Brazil. After its application, answer sheets are sent online to Instituto Butantan for grading. The sixteen top-ranked students are selected for the third and final round.

The third round takes place at Instituto Butantan and consists of one week of practical training and assessments. The top four students at this round are selected to participate in the IBO. The fifth to eighth placed are selected to participate in the Ibero-American Olympiad Biology.

Number of students in first round

In 2019, 120,000 students participated in the first round of our NBO.


Round 1: 30 multiple choice questions. Students take the exam at their own schools

Round 2: 100 multiple choice questions. Students take the exam at selected schools in their home state

Round 3: Written and practical exams. The exams are held at Instituto Butantan


The training done by students in the first and second rounds depends on the students and their schools, and is likely widely variable. In the third round, which may be considered a training camp, the students go through a one week of practical training.

Study materials

There are currently no specific materials developed for the training of students. In our homepage many tests of former OBB are available to better prepare students for the OBB rounds.

Awards & prizes

The first round does not award students any prize.

The second round awards a total of 150 medals (gold/silver/bronze).

The third round

All participating students of our NBO receive certificates.

Some public Universities are offering entrance to National and International Scientific Olympiad medalists, using a composite score of all medals won by the student.


Type of students

The OBB applies the same rules as IBO regarding students who can participate. Only students that are duly enrolled in high school, as well as a 19-year limit, are allowed to participate in the OBB.

School year

In Brazil, the standard school year starts at late January and ends at late November.

Biology hours/week

Varies, but is commonly 4 hours/week.

Hours of Classes/week

Varies, but is commonly 30 hours/week.

Public Relations

Statistics over the years
  • 2019: 120000 students from 3000 schools (10% of eligible schools)

In 2020, only the first round of the OBB took place, with XXX000 participants.

Media coverage

The host institution (Instituto Butantan) issues press releases and social media posts.