A recent checklist of mosses in Paraguay included three species of Holomitrium Brid.: H. arboreum Mitt., the newly reported H. olfersianum Hornsch. and the endemic H. paraguense Besch. A review of Holomitrium from the Neotropics revealed that H. paraguense was a new synonym of H. olfersianum. Lectotypes are newly proposed herein for H. olfersianum and H. paraguense based on material from the Hampe and Bescherelle herbaria in the BM. Two species of Holomitrium (H. arboreum and H. olfersianum) are now known to occur in Paraguay in the states of Alto Paraná, Canendiyú and Paraguarí.