The current article addressed middle school (13-15 years old) students' science-related career awareness (SCA) and aimed to determine the effects of a longitudinal intervention, which focused on integrating career education into science teaching, using a pre- and post-test design. During the intervention, five teaching/learning modules (TLMs) were implemented in science lessons that enabled students to experience being (1) an electrical engineer, (2) a food technologist, (3) a forensic scientist or a civil engineer, (4) a team member of oil catastrophe simulation clean-up team, and (5) a customs' officer. Concept mapping was used to determine the changes in students' SCA. The suitability of this technique was validated through semi-structured focus group interviews. It was found that concept mapping enabled detection of progression in the intervention students' SCA among both boys and girls. The interviews provided valuable input on how students interpreted science-related occupations and relevant competences, when constructing their concept maps. An implication from this study was that SCA supportive teaching and learning modules or other similar teaching methods needed to be an inherent part of science teaching to support students making well informed decisions, either towards or away from science-related careers.