Introduction:
Medical education is well known for its difficulty. However, one of the ultimate aims of medical education is academic success. Therefore, undergraduate medical students are facing multiple factors during academic courses that correlate with their academic performance.

Aim:
We aimed to study factors associated with academic performance among clinical year medical students in a Southern Thailand medical school.

Material and methods:
168 medical students in the fourth and fifth year of a southern Thailand tertiary teaching hospital participated in this cross-sectional questionnaire-based study; over March 2021. We developed the questionnaire to cover all factors affecting academic performance, indicated by accumulated grade point average (GPAX). The data were analyzed using the R Program (v. 4.0.4).

Results and discussion:
Of 168 medical students, 55.5% were women. Median GPAX was 3.22. The multivariate analysis showed that a higher GPAX was associated with time spent on study more than 4 h per day (P = 0.013), time spent on social networks more than 4 h per day (P = 0.004), strong motivation to become specialists (P = 0.007) and having a good relationship with family (P = 0.034).

Conclusions:
Medical students' academic achievement was associated with increased study hours, time spent on social networks, motivation to become specialists, and having a good relationship with the family. However, we recommend further longitudinal studies to evaluate and confirm factors that affect academic performance.