The problems of the decreasing enrolment of science students at secondary school level as well as the lagging science and mathematics achievement and literacy of Malaysian secondary students in international assessment studies point to a serious challenge for the government to improve Science, Technology, Engineering and Mathematics (STEM) education. One of the key steps that can be taken is to identify the current assessments in STEM related subjects at the secondary school level because according to OECD (2005), assessment is an integral component of the education process. Thus, this study (which is part of a larger research project) aimed to examine secondary students' perceptions of assessments in STEM related subjects. The researchers employed a cross-sectional survey research design and the sample comprised of 1215 Form Four students from three categories of secondary schools in Peninsular Malaysia. A five-point Likert scale questionnaire containing 10 items was used to elicit Form Four students' perceptions of assessments such as examinations or assignments in STEM related subjects. The questionnaire was developed based on the STEM Education Quality Framework (2011). Analysis of 1005 complete questionnaires from the sample indicated that the students showed positive overall perceptions of assessments in STEM related subjects. The results also indicated that there was a statistically significant difference in overall perceptions of assessments in STEM related subjects in terms of school category but there was no statistically significant difference in overall perceptions of assessments in STEM related subjects in terms gender.