OBJECTIVE: To assess associations between subjective well-being (SWB), religiosity, anxiety and other factors in a sample of Brazilian medical students from a public university in northeastern Brazil. METHODS: The present study followed a cross-sectional, observational, analytical approach. Data were collected by administering a self-applicable questionnaire composed of questions focused on sociodemographic data and based on the Satisfaction With Life Scale (SWL), Positive Affect and Negative Affect Scale (PANAS), Penn State Worry Questionnaire (PSWQ), and the Duke Religiosity Index (DUREL). RESULTS: The sample comprised 417 medical school students (73.54% of all the enrolled students). The medical students assessed presented a medium level of satisfaction with life, low mean positive emotion levels and high anxiety/uneasiness levels. Surprisingly, lower anxiety and intrinsic religiosity (IR) scores were associated with higher scores in the two SWB parameters (positive emotions and satisfaction with life). Furthermore, the factors leisure activities, good sleep quality, financial support, age, and gender were associated with the highest SWB scores (with emotional and cognitive components, or with only one of these two components). CONCLUSIONS: Data in the current study corroborated the negative association between SWB and anxiety; however, in opposition to the literature, they also evidenced a negative association between SWB and IR. In addition, the present research signaled the need for creating preventive intervention programs to increase SWB through positive psychological techniques and/or to decrease anxiety by applying, for instance, cognitive-behavioral therapy paradigms and/or mindfulness techniques to medical students.