Frequency of airborne fungal spores have been recorded and measured thrice a day using a rotorod sampler in few selected occupational environments during summer season (March-May, 1995) in Calcutta. A total of 24 spore types were recorded and identified, including relatively high frequency of Aspergilli, Alternaria sp., Nigrospora sp., Periconia sp., etc. In a partially indoor environment like the entry hall of Sealdah station, underground subway of Howrah station, etc., where streams of people pass round the clock, `Aspergilli' concentration was found to be quite high (2000-8000/m to the power of 3 of air). Results obtained from the exposure of petriplates with malt extract agar and Czapec Dox agar media, were corroborated with the results recorded through Rotorod sampler. The trapped types originated from various Aspergillus species like A.niger, A.japonicus, A.fumigatus, A.candidus, etc. Colony forming units of A.niger and A.japonicus were of a relatively high frequency. Aspergillus fumigatus was selected for clinical investigation because of its abudance in two market areas of Calcutta (Sukia street market and Manicktala market).