Secondary school students in the Netherlands already face future-oriented decisions about their educational careers, which are expected to be informed by their interests in specific vocations or occupations. However, vocational interest assessment tools generally do not account for the possibility that students are interested in multiple vocational domains, potentially challenging students' future-oriented decision-making processes. The present study examines the different combinations of vocational interests that secondary school students have and explores how the both differentiated and nondifferentiated character of these interests' structures is associated with students' educational and career-oriented decision-making processes. A latent profile analysis on six realistic, investigative, artistic, social, enterprising, and conventional interests revealed seven distinct vocational interest profiles across a sample of 358 Grade 9 students, of which 40.8% had a nondifferentiated interest structure (i.e., a low, neutral, or broad vocational interest) and 59.2% had a differentiated interest structure (i.e., a social dominant, enterprising-conventional dominant, realistic-investigative dominant, or artistic-social-enterprising dominant interest). This finding shows that many secondary school students show similar levels of interest across different vocational activities. Additionally, associations between the differentiated and nondifferentiated structure of these profiles and students' educational track choices and career image specificities were examined. Our results extend prior work by showing that having a nondifferentiated interest structure does not necessarily mean that students are more uncertain about their educational or career choice. We suggest that future research can further explore the associations between vocational interest structures and future-oriented decisions.