Optimal conditions for the preservation of mushroom cultures in sterile distilled water were investigated. Mycelial disks from 12 mushroom cultures were preserved at room temperature, $5^{circ}C,;-20^{circ}C$ and $-75^{circ}C$ using sterile water and 6 cryoprotectants for 12 months. The maximal viability of mycelial disks was observed at room temperature and $5^{circ}C$ with the value of 91.7%. At $-75^{circ}C$, the viability was highest in polyethylene glycol (PEG) and lowest in 10% dimethyl sulfoxide (DMSO). The average mycelial growth was highest for disks preserved at $-75^{circ}C$ in PEG. PEG was the most suitable for the preservation at $-75^{circ}C$, although this chemical has rarely been used as a cryoprotectant in fungal culture preservation. The laccase isozyme patterns of the preserved isolate of H. ferrugineum were not changed during preservation at $5^{circ}C$ in sterile distilled water as compared to that of slant culture.