Nearly 14 million species are estimated to exist on Earth, of which 1.8 million have been identified, and new species are being added to the world of science every day. Therefore, scientists are aware that there are still unidentified species living globally. Biodiversity is a wide concept encompassing all living things in our living space. This study aims to determine the level of knowledge of 8th-grade students about biodiversity and some variables that may impact it. The study's sample consisted of 286 students studying in the 8th grade of all secondary schools in Oltu district of Erzurum province in the 2022-2023 academic year. The survey model was used in the study. For the data collection tool, the "Biodiversity Achievement Test" and "Plant and Animal Recognition Questionnaire" were used for the students to recognize the plants and animals in their immediate surroundings. The data were analyzed through the SPSS program. As a result of the data analysis, it was concluded that girls were more successful in biodiversity. The rate of students' recognition of plants in their immediate environment (39.44%) was lower than the rate of recognition of animals (64.07%).