Cognitive interest is a vital learning motive for the successful learning process. Nowadays students' interest about science and mathematics are decreasing. The aim of the study is to explore the cognitive interest of Grade 9 students in science and mathematics. Students were surveyed and it helped to explore the respondents' cognitive activity and the cognitive interest regarding the understanding of causal relations, research activity and the solution of practical problems. The level of cognitive interests on the three level scales is average for the whole sample of respondents. The survey shows that students do not possess explicit cognitive activity; learning happens rather passively, without initiative; however, they have rather pronounced interest to explore and solve problems connected with the real life. Some implications for teachers on how to increase learners' cognitive interest are provided in the conclusion. [This paper was presented at the 1st International Baltic Symposium on Science and Technology Education (BalticSTE2015) 'State-of-the-Art and Future Perspectives', June 15-18, 2015, Siauliai, Lithuania.]