This study examined the perceptions of 6th grade middle school students regarding physics and physics-related careers. The overarching goal of this work was to understand similarities and differences between girls' and boys' perceptions surrounding physics and physics-related careers as part of a long-term effort to increase female interest and representation in this particular field of science. A theoretical framework based on the literature of girl-friendly and integrated STEM instructional strategies guided this work to understand how instructional strategies may influence and relate to students' perceptions. This convergent parallel mixed-methods study used a survey and focus group interviews to understand similarities and differences between girls' and boys' perceptions. Our findings indicate very few differences between girls and boys, but show that boys are more interested in the physics-related career of engineering. While girls are just as interested in science class as their male counterparts, they highly value the social aspect that often accompanies hands-on group activities. These findings shed light on how K-12 science reform efforts might help to increase the number of women pursuing careers related to physics. [This paper is part of the Focused Collection on Gender in Physics.]