Research on the advantages and disadvantages of project-based learning (PBL) among gifted pupils studying physics is scarce. This mixed-methods study investigates engagement, experiences, and learning outcomes among gifted Finnish upper-secondary-level students learning physics through PBL. A six-lesson PBL module on basic Newtonian mechanics was designed and implemented for a group of gifted students (N = 38), whereas a traditional teacher-driven approach was used among a control group (N = 38) of gifted students. Data were collected by means of a questionnaire, interviews and a physics test. According to the results, PBL met the preconditions (challenge, skill, interest) for engaging the students in learning physics. It generated interest in learning among the vast majority, but not as many found it challenging. The findings also highlight the impact of autonomy when learning through PBL. No differences in overall learning outcomes were found between the groups.