It has been found that participation in informal, year-long STEM programmes for "primary school children" encourages further STEM learning and motivates STEM career aspirations. To date, no previous research has investigated such programmes. The study's goals were to collect and analyse demographic data about the 3rd-6th grade participants in such programmes (N = 276), to identify the reasons that led them to participate in the specific programmes (e.g. science, computers, robotics) and (3) to map their career aspirations. Qualitative data were obtained from two open-ended questions and analysed through summative content analysis. Key findings included: More boys participated in the programmes than girls; younger students participated more than older students; predominant motivations cited for participating in the programmes were interest and enjoyment as opposed to practical utility concerns; more 5th-6th graders cited utility concerns than 3rd-4th graders; about 1/3 of the participants had STEM career aspirations; more 5th-6th graders aspired to STEM careers than 3rd-4th graders; more 3rd-4th grade boys aspired to STEM careers than girls. We concluded that participation in these programmes signifies entry into STEM career pathways at a much earlier age than previously reported.