Purpose: This study assesses the effects of junior enterprises (JEs) on the entrepreneurial attitudes and intentions of engineering higher education students, compared to a group of social sciences students. Design/methodology/approach: This research analyses a sample of 132 students enrolled in engineering higher education courses in Portugal and Brazil, while 83 of the respondents being involved in a JE and 49 not. The authors compare this group to another group of 176 social sciences students from several higher education courses, while 93 being enrolled in JE and 83 not. Findings: The results show that students enrolled in JEs show higher levels of entrepreneurial intention (EI), as well as their antecedents such as attitude towards the behaviour (ATB), perceived behavioural control (PBC) and social norms (SN), and the impact of this extracurricular activity is higher on engineering students than on social sciences students. Also, country and gender differences were found in some variables. Research limitations/implications: Further studies are needed to confirm the results in a broader population and in other countries. Also, the study addressed attitudes and intentions but not actual behaviour due to the time lag problem. There is also the risk of self-reported bias on the answers due to social desirability bias, for example. Finally, because JEs have their own recruitment process, there is a possible "self-selection problem" of students who might have previously developed some of entrepreneurial attitudes and skills assessed by the questionnaire. Practical implications: The results have important implications for engineering higher education institutions. Despite many of them provide entrepreneurship training courses, they should also encourage students to join extracurricular activities or even create their own at their institution to complement their skills' development. Also, teachers should be encouraged to integrate these activities into their subjects, avoiding a major barrier to the participation in extracurricular activities which is the students' time constraints. Finally, participation in extracurricular activities can be promoted by institutions in many ways, such as allowing students to obtain academic credits or through supporting financially or logistically the organisations that promote these activities. Social implications: This study contributes to the discussion on how to promote the development of entrepreneurial competences in young people that soon will enter the labour market. Originality/value: This study contributes to the discussions on the value of extracurricular activities, such as the enrolment in JEs, to the development of entrepreneurial attitudes and intention on the training of the next generation of engineers capable of facing future worlds' challenges.