Purpose: To determine motives and attitudes towards life-sustaining treatments by clinical and preclinical medical students. Methods: This was a scenario-based questionnaire that presented patients with a limited life expectancy. The survey was distributed among 455 medical students in preclinical and clinical years. Students were asked to rate their willingness to perform LSTs and rank the motives for doing so. The effect of medical education was then investigated after adjustment for age, gender, religion, religiosity, country of origin, and marital status. Results: (...) Preclinical students had a significantly higher willingness to perform LSTs in all cases. This was observed in all treatments offered in cases of a metastatic oncologic patient and an otherwise healthy man after a traumatic brain injury. In the case of an elderly woman on long-term care, preclinical students had higher willingness to supply vasopressors but not perform an intubation, feed with a nasogastric tube, or treat with a continuous positive air-pressure ventilator. Both preclinical and clinical students had high willingness to perform resuscitation on a twelve-year-old boy with a TBI. Differences in motivation factors were also seen. Discussion: Preclinical students had a greater willingness to treat compared to clinical students in all cases and with most medical treatments offered. This is attributed mainly to changes along the medical curriculum. Changes in reasons for supplying LSTs were also documented. (shrink)