There is widespread consensus that internships provide great opportunities for engineering students to develop diverse knowledge and competencies. Yet, compared to learning in the classroom, learning in the workplace is less predictable. This study aims to address the research question 'What are engineering students' perceived learning outcomes from their internship experience?' by using a qualitative approach to pinpoint commonalities and differences in students' perceived learning outcomes. Content analysis and constant comparative analysis were used to analyse interview data collected from ten engineering students in Hong Kong. Four categories of learning outcomes were revealed: knowledge, academic-related generic competencies, non-technical generic competencies and technical competencies. Our findings are contrary to the literature indicating that most engineering interns perceived the development of technical competencies (e.g. information technology (I.T.) skills) and non-technical generic competencies (e.g. teamwork skills and positive attitudes). Diversity in engineering students' perceived learning outcomes of internship was subsequently illustrated by a provisional framework. The findings help pave the way for constructive alignment in internship course design such that identification of students' perceived learning outcomes will facilitate the setting of realistic and clear intended learning outcomes.