Introdução: Hepatitis E has recently been highlighted due to its association with increased mortality in pregnant women and babies and the possibility of becoming a chronic disease in immunocompromised patients. Objetivo(s): To determine the prevalence of HEV infection in immunocompromised patients who underwent solid organ and bone marrow transplantation. Material e Métodos: Cross-sectional study was carried out at the Complexo Hospitalar Universitário Professor Edgard Santos (HUPES) and Hospital São Rafael (HSR). Approximately 250 immunocompromised patients will participate in the study: 50 liver transplant patients, 100 kidney transplant patients, and 100 bone marrow transplant patients. The prevalence of HEV infection was determined by the detection of HEV-RNA using RT-qPCR method (Realstar HEV RT-PCR kit 2.0, Altona Diagnostics) and by screening for anti-HEV IgG and anti-HEV IgM antibodies by the ELISA (Wantai). Resultados e Conclusão: To date, 95 post-bone marrow transplant (post-BMT) patients have been recruited from HUPES. Most were male (51%), mean age of 41.7 years (ranging from 17 to 70 years), residing in the great Salvador (36%), and self-declared black and brown (80%). Among the percutaneous risks, we describe: received a donation of whole blood/blood products (94%), performed invasive dental (93%) and surgical procedures in addition to BMT (59%), had a tattoo (17%), used inhalable drugs (7 %) and non-disposable syringes (7%). No participant reported injecting drug use. Among the nonpercutaneous risks, we analyzed: they have already had oral sex (42%) and anal sex (23%), have the habit of going to the beach (43%) and have had contact with water from floods, floods and/or flooding (38%). The analyzes of contact with herd animals and food preference are being carried out. Anti-HEV IgG antibody seroprevalence was performed in a subgroup of 85 samples, of which only one was reactive (1.2%; 95% CI: 0.0-6.4%). None tested positive for anti-HEV IgM (0%). We have not yet started molecular tests for the detection of HEV-RNA, as well as the collection of data and samples from patients who underwent solid organ transplantation. Conclusion: Although the data are preliminary, post-BMT patients have already been exposed to HEV. New data collection and viremia research will be able to identify more cases and confirm chronic infection among solid organ and bone marrow transplant patients.