Anonymized clinical dataset of 8 patients who developed graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation at Cheikh Khalifa University Hospital, Casablanca, Morocco, between 2021 and 2025. Data include patient demographics, donor characteristics, conditioning regimen, GvHD type, grade, treatment, and outcome. All data are de-identified according to the Safe Harbor Method.