Laboratories play a crucial role in the undergraduate science curriculum and the effectiveness of learning in laboratories is influenced by learners’ interactions with other students, the instructors, and the equipment used. In this study, a pre-lab survey was used to collect information about students’ expectations of interactions in chemistry laboratories and how they can be ranked according to their importance. Post-lab surveys were used to capture students’ perspectives about the frequency of interactions that existed in laboratory sessions they had completed. Direct observations of some laboratories were also conducted principally to validate students’ self-reported interactions. The data were also sorted by three levels of student achievement in order to relate students’ expectations of the importance of different interactions (pre-lab survey) and their self-reported frequency of interactions (post-lab survey) with their laboratory grades. Results from the pre-lab survey showed that student–instructor interactions were anticipated to be the most important ahead of conducting the laboratory activity, whereas results from the post-lab surveys showed that the most frequent interactions occurred between students. Students’ self-reports (post-lab survey) and the direct observations agreed well suggesting that the post-lab survey is a robust tool for capturing the frequencies of student interactions in this and future studies. The results also showed that students gaining high grades both anticipated the importance of, and then engaged more frequently in, two-way communications with both students and instructors whereas students with lower grades placed a relatively higher reliance upon passive interactions such as the pre-lab briefing, the laboratory manual and internet sources. Finally, recommendations are offered to curriculum designers, instructors and students based on the overall findings of the study.