Researchers' motivations are important for high-quality research and the productivity of the scientific system, but remain largely uninvestigated. Using three studies, we tested the usefulness of Achievement Goal Theory (AGT) for describing research motivations, investigated which goals researchers pursue, and examined their associations with job burnout/engagement and professional learning. Interviewing 20 researchers (Study 1), we found that most of their goals in the research context were classifiable as achievement goals. Apart from mastery and performance goals that are well-established in the AGT literature, they also mentioned relational and work-avoidance goals. Mastery goals comprised task and learning standards, performance goals comprised appearance and normative strivings. In Study 2, we used a standardized questionnaire to assess these goals in 824 researchers, along with burnout/engagement, professional learning time, and professional learning gains. Results confirmed the separability of all conceptualized goals, measurement invariance across academic status, and differential patterns of associations with burnout/engagement and professional learning. In Study 3, we analyzed these constructs in 471 researchers at two time points, six months apart. Results attested measurement invariance over time. Cross-lagged analyses documented similar associations as in Study 2. Learning approach and relational goals had positive effects on professional learning; appearance avoidance and workavoidance goals were negative predictors. In contrast, burnout was negatively predicted by normative avoidance goals. However, high initial burnout levels were associated with reduced task approach and learning approach, and stronger work-avoidance goals six months later. Taken together, the results highlight the usefulness of AGT for understanding researchers' motivations, and their relatedness with professional learning and well-being at work.