Goal orientation theory has long recognized both stability and variability in peopleβs preferences for different types of goals in achievement contexts. However, empirical examination of this fundamental theoretical tenet about dispositional goal orientations remains an essential need in extant scholarship. In a field study of a multi-month, job-related training program designed to instruct foreign language capabilities (N = 972), we examined within-person fluctuations in dispositional goal orientations over time and the influences of this variability on multiple learning outcomes. The results of longitudinal measurement invariance analyses as well as latent growth models depict both stability and significant within-person variability in dispositional goal orientations over time. Our findings further indicate that this fluctuation holds consequences for both skill-based and affective learning outcomes. We discuss the implications of our findings for future goal orientation theory and research, as well as for training practice