The use of project work (PW) or project-based learning has escalated in Singapore since its inception by the Ministry of Education in the year 2000. There is however little information on students' motivation, and their experience of PW over time. This study sought to identify homogeneous groups of students with distinct perceived locus of causality (PLOC) profiles using a cluster analytic approach, and to examine group differences in their perceived psychological needs, emotions, metacognition, and perceived skills learned in PW over time. Four distinct clusters of students were identified. The "high self-determined/low controlled" group was the most adaptive cluster, and the "low self-determined/high controlled" group was the least adaptive cluster. The study affirms that the self-determination theory (SDT) can provide important insights into the motivational processes in PW. It establishes that students' motivational regulations and their perceived needs satisfaction at the start of PW are related to their experience of and learning in PW. (Contains 3 figures and 5 tables.)