This study investigated Grade 9 students’ attitudes towards science, technology, engineering, and mathematics (STEM) and the extent to which their attitudes impacted on their academic achievement in Integrated Science. An adapted Students’ Attitudes Towards STEM instrument (Friday Institute for Educational Innovation, 2012) was piloted on 67 high school students in Jamaica and yielded a Cronbach alpha value of 0.821. It was then administered to 259 Grade 9 students from four high schools. The students’ achievement in science was measured by Integrated Science examination grades earned in the previous term. The students had moderately positive attitudes towards STEM, with the exception of mathematics. There was a weak but positive correlation between students’ academic performance in Integrated Science and their attitudes towards STEM, except for the areas of Engineering and Technology. Based on regression analysis results, 12.8% of the variation in students’ science scores can be explained by their attitudes towards mathematics. The established relationship between the two variables shows that teachers need to find ways to encourage students to develop positive attitudes towards STEM, particularly mathematics.