Postmortem examination of a 35-year-old parous woman who died suddenly revealed a hydatid cyst mass located at the right ventricular outlet, with a grossly discernible defect opening to the pulmonary outflow tract. Pulmonary hemorrhage, follicular bronchitis, and bronchiolitis also were present, with severe acute purulent exudation in the airways. Hydatid cyst complications must be kept in mind when dealing with sudden deterioration and death in patients who are residents of regions where echinococcosis is endemic.