Caffeine (1,3,7-trimethylxanthine) consumption among students is known to increase alertness and energy, as well as to alleviate stress.There has been an increase of caffeine consumption amongst young adults. Currently, there are no studies regarding caffeine consumption and its influence on mental health among Malaysians. We aimed to determine the relationship of caffeine consumption with depression, anxiety and stress among medical students.A cross sectional study was conducted among medical students in the Faculty of Medicine, Universiti Kebangsaan Malaysia. Data were collected via an online survey using two questionnaires, namely the semi-quantitative Food Frequency Questionnaires on Caffeine Intake and Depression, Anxiety and Stress Scale (DASS-21).A total of 262 medical students completed the survey. The prevalence of depression, anxiety and stress was 9.2%, 16.8% and 1.1%, respectively. Majority of students (98.5%) consumed caffeine from coffee, tea, soft drinks, energy drinks and chocolate drinks/food. The median daily caffeine consumption among consumerswas67.98 (25th,75thpercentile: 24.83, 139.71) mg/day.There was a significant association between race and anxiety (p=0.038) in which the Malay students had the highest prevalence (21.1%), followed by Indian (16.1%), other races (15.4%) and Chinese students (3.8%). Caffeineconsumption did not influence mental health of medical students in this study. Anxiety is the most prominent mental health problem among them. We recommend a programme tailored to medical students in recognising symptoms of mental health problems so that early intervention can be carried out.