Cryptococcus neoformans was isolated on 276 occasions as follows: from pigeon faeces, 159 (45%) of 349 samples; pigeon crops, 39 (50%) of 80 crops; from drinking water, 37 (74%) of 50 samples; from the atmosphere, 3 strains in a contaminated loft. It was also recovered from 38 (19%) of 200 samples of canary faeces. It is possible that C. neoformans survives in the crop of pigeons and occasionally passes to the faeces where it multiplies. The factors influencing its presence are: the irregular cleaning of lofts, overcrowding and air-pollution from poor ventilation.