In recent years, the organizations of the science fairs at schools have been emphasized on. Science fairs are important since students' perceptions, attitudes, and achievements towards sciences are affected positively by the science fairs. It is important to carry out studies for science fairs and follow up this process in this context. This study aims to evaluate the effectiveness of the 4006 coded TUBITAK science fairs and the problems experienced by sciences teachers during the preparation and implementation stages of the fair. For this purpose, the study was carried out within the framework of the Phenomonographic approach, which is one of the qualitative research methods. The study group consists of 20 sciences teachers who participated in the support program of TUBITAK science fairs coded 4006 in the 2018-2019 academic year in Istanbul. In the study, a semi-structured interview form was used as a data collection tool. When the interview form was examined; It was determined that the majority of the teachers participating in the study demonstrated positive thoughts towards 4006 TUBITAK science fairs. Teachers stated that students who participated in science fairs developed skills such as imagination, active participation, self-confidence, socialization, work awareness, and responsibility.