Our study focused on describing first-year university students' motivational profiles and examining differences in academic achievement based on these profiles. Data on academic motivation of 755 students in the field of mathematics and natural sciences were collected before the start of their bachelor's degree program; data on GPA were collected at the end of the first year. A two-step cluster analysis indicated a four-cluster solution: Students in cluster 1 scored high on intrinsic motivation (IM) and extrinsic motivation (EM), but low on amotivation (AM). Students in cluster 2 scored high on IM and low on EM and AM. Students in cluster 3 scored high on EM and AM. Students in cluster 4 scored lower on IM and EM and higher on AM. Students in cluster 2, who had the most self-determined motivational profile, obtained the highest GPA. Our study suggested that distinguishing students based on motivational profiles may be helpful in identifying students at risk for lower academic achievement or even dropping out.