Histoplasma capsulatum is an opportunistic pathogen which can lead to a wide variety of clinical presentations in the immunocompromised host. Post-transplant histoplasmosis in hematopoietic cell transplant recipients is exceedingly rare, with an incidence of <1%. We present a case of acute caecal perforation resulting from disseminated histoplasmosis in a patient who had undergone autologous bone marrow transplant for plasma cell dyscrasia. This is a 71-year-old patient who initially presented due to progressive weakness associated with shortness of breath.