Objectives: Infections are a major cause of morbidity and mortality in patients with myelodysplastic syndromes (MDS). The objective of the MINDSET study was to evaluate haematologists' management of infection prevention in MDS patients using a case vignette study and to assess the availability of guidelines. Methods: We conducted a web-based, nationwide survey amongst haematologists in the Netherlands between September and December 2021. The survey included a set of case vignettes. In addition, the availability of protocols was evaluated. Results: Sixty responses were obtained (23.6%). These responses were well distributed across hospital types as well as level of experience. No protocols regarding infection prophylaxis specifically for MDS patients were received. In the case vignette of a 75-year-old MDS patient, respondents would primarily prescribe infection prophylaxis in case of recurrent infections (96.7%) and neutropenia (75.0% for absolute neutrophil count [ANC] < 0.2 × 10 9 /L and 53.3% for ANC < 0.5 × 10 9 /L), especially in combination with hypomethylating agents (80.0%), lenalidomide (66.7%) or chemotherapy (51.7%). Respondents would predominantly choose antibacterial agents (85.0%), followed by antifungal agents (71.7%). Conclusions: This study showed diverse reasons and considerations of haematologists regarding whether to prescribe infection prophylaxis in MDS patients. Given the seriousness of infections in MDS patients, patient-tailored recommendations might be valuable in clinical decision-making.