There is a variation in terms of how researchers perceive the nature of research work. Previous research has mainly looked at the members of academia who already have established themselves in the scholarly community. We aimed at exploring the ways in which doctoral students perceived their thesis project and further, the relations of such perceptions to well-being and study engagement. The participants were 669 doctoral students from medicine, humanities, and behavioral sciences from a Finnish university who answered a questionnaire, including both structured and open-ended questions. The analysis was conducted by triangulating qualitative and quantitative data. The results showed that students' perceptions varied, ranging from perceiving the thesis as a "product" to viewing it as a "process" of developing expertise. Further, the results indicated that perceiving work on the thesis as a process was most advantageous in terms of experienced well-being and study engagement. (Contains 8 tables.)