Two edible mushrooms, Pleurotus eryngii and Panellus serotinus, have been investigated chemically. Two new sterols, 5a,9a-epidioxy-8a,14a-epoxy-(22E)-ergosta-6,22-dien-3b-ol (1) and 3b,5a-dihydroxyergost-7-en-6-one (2), have been isolated from P. eryngii, together with six known ones (3—8). Compound 1 was also isolated from P. serotinus. The structures of the new compounds were elucidated on the basis of their spectral data.