Abstract Background A large number of studies are devoted to medical errors, but only a few focused on the problem’s victims of these errors face. Prospective comparative studies on this topic are absent. The aim of this prospective comparative study is to fill this gap of scientific knowledge that may help to improve the care for victims. Methods Data were collected in the Longitudinal Internet studies for the Social Sciences panel, based on a random sample of the Dutch population. Surveys were conducted in March–April 2018 (T1response = 82.1%) and March–April 2019 (T2response = 80.1%). We assessed medical errors and potentially traumatic or stressful events between T1 and T2, and mental health, work, financial, religious, family, legal/administrative and physical problems at T1 and T2 (Ntotal = 4711). Results In total, 79 respondents were affected by medical errors between T1 and T2, and 2828 were not affected by any event. Of the victims, 28% had high PTSD symptom levels at T2. Stepwise multivariate logistic regression entering all problems at T1 and demographics showed that victims compared with controls significantly more often had all assessed problems at T2, except family problems. For instance, victims more often had mental health problems (29.5% vs. 9.3%; adj. OR = 3.04, P = 0.002) and financial problems (30.4% vs. 6.6%; adj. OR = 4.82, P < 0.001) at T2. Conclusions Victims of medical errors more often face various non-physical problems than others. Care for victims should therefore, besides physical health, also include the assessment and targeting of their problems regarding mental health, work, religion, legal issues and finance.