This study examined the relationships between achievement goals, motivation instability, and learning persistence in asynchronous distance classes by focusing on mastery goals and performance-avoidance goals. A longitudinal online survey was conducted among university students in Japan at two time points. The first survey had 171 respondents. Out of them, 91 responded to the second survey. The data of the 91 students were analyzed. The results of partial correlation analysis indicated that mastery goals were negatively related to motivation instability and lack of persistence, while performance-avoidance goals were positively related to lack of persistence and unrelated to motivation instability. Mediation analysis indicated that the negative indirect effect of mastery goals on lack of persistence via motivation instability was found, and that the direct effect of mastery goals on lack of persistence was not found. The results highlight the vital role that mastery goals play in learning during asynchronous distance classes. Achievement goals, motivation instability, and learning persistenceThis study investigated the relationships between achievement goals, motivation instability, and learning persistence among Japanese university students in asynchronous distance classes. A longitudinal online survey was conducted among university students in Japan at two time points. The results indicated that mastery goals facilitated learning persistence by suppressing motivation instability. In other words, learners who hold mastery goals seem to be able to focus and engage in learning to understand class material because their attention is focused on expanding their abilities, rather than comparing themselves to others. Such learners, therefore, have smaller fluctuations in motivation during learning and can engage in learning consistently and persistently. We believe that our study makes a significant contribution to the literature because while past studies have only explored the relationship between achievement goals and motivation levels with regard to the achievement goal theory, the present study demonstrated that achievement goals, particularly mastery goals, are associated with motivation instability. This finding is of great significance as it paves the way to expand achievement goal theory to demonstrate this new role of achievement goals in learning.