PurposeThis paper investigated the impact a camp on informal science, technology, engineering and mathematics (STEM) had on students' perceptions of STEM fields and careers.Design/methodology/approachA quasiexperimental design was used to assess students' perceptions toward STEM fields and careers. Secondary students (n = 57) who participated in the STEM summer camp completed STEM projects, went on lab tours and attended panels during the one- or two-week residential camps. Students completed a STEM Semantics survey to assess their perceptions prior to and after attending the camp. Descriptive statistics, Cohen's d effect sizes, paired sample t-tests and Pearson's correlation were conducted to analyze the data.FindingsResults suggested that although there was no significant change in students' dispositions toward each individual STEM field, there was a statistically significant improvement of students' perceptions of STEM careers (p = 0.04; d = 0.25). Furthermore, the results of the Pearson's correlation indicated that there was a statistically significant positive association between perceptions of a STEM career and perceptions in science, mathematics and engineering.Research limitations/implicationsThis suggests that various components of the informal learning environment positively contributed to students' perceptions toward STEM careers. Implications from the study indicate that when students are engaged in hands-on science or STEM PBL activities and have opportunities to be exposed to various STEM careers, their perceptions of STEM pathways will improve.Originality/valueThese results may influence future curriculum and the organization of future STEM camps by encouraging teachers and camp directors to integrate practical hands-on STEM projects and expose students to potential STEM pathways through lab tours and panels of STEM professionals.