Background In 2014, in Brussels, a group of undocumented migrant workers started a hunger strike. A loophole in Belgian migration law allows very sick people to stay in the country to recuperate. Undocumented migrants jeopardize their health to be able to obtain a temporary permit and a way out of misery. The monitoring of the hunger strike was done by young, committed but inexperienced health professionals.Methods At the end of the hunger strike, two focus groups were held to find out the dilemmas confronting the health professionals.Results Eighteen out of 29 health professionals participated. They mentioned their curiosity to gain new insights into living conditions among undocumented people and the reasons why they started the strike. They were puzzled by the paradox of wanting to die to get a better life and refusing medical advice. They wondered about their role and commitment as a caregiver. Some were deeply touched by the experience and reacted emotionally while others deepened their engagement. Symptoms of Secondary Traumatic Stress, such as re-experiencing and avoidance were observed. The participants themselves also proposed improvements to the monitoring. Conclusions Even though only a small number of health professionals were questioned, we detected a lot of preoccupations and contradictions in their reactions. To be able to process these a close follow-up and evaluation of the monitoring of a hunger strike is mandatory. We also propose that prevention, early detection and treatment of Secondary Traumatic Stress should become part of formal medical education.