In 2014–2017 an investigation was carried out into the occurrence of fungal storage diseases of five apple varieties (Red Jonaprince, Gala, Golden Delicious, Gloster and Ligol) in the Sandomierz orchard region. The fruit was stored at a CA cold storage room with ULO controlled atmosphere for six months. Occurrence of eight storage diseases was found. The most frequently occurring disease was bull’s eye rot and the losses caused thereby were even 24% of the affected fruit. The cultivars most susceptible to this disease were the Golden Delicious and Ligol apples; the least susceptible were the Gloster ones. The apples were significantly less affected by the fungi that cause brown rot, grey mould rot, blue mould rot and apple scab. Very seldom were the symptoms of calyx end rot, mouldy core and core rot, and anthracnose. Varying severity of infection of the varieties was noted in each season of observation.