Algae are ubiquitous and omnipresent. They are dispersed effectively by air dried condition. Studies across the continents revealed their presence both indoors and outdoors. In dispersed state they show their impact either as contact or respiratory allergens in human beings. In a two year study carried out in Chalisgaon (Maharashtra), experiments were conducted both indoors and outdoors to isolate airborne and dust-borne algae. S1, S2, S3, are outdoor sites whereas S4, S5 & S6 are indoor sites. Additionally, experiments were conducted round-the-clock by using petriplates placed inside the volumetric airsampler in different months. House (floor & bed), street, foot, foot-wear dust samples were used to culture algae. Average number of CFUs recorded at S1, S2, S3, S4a, S4b, S4c, S5 & S6 were 695, 393, 218, 265, 246, 109, 128, 114 respectively. More than 90 species distributed under 38 genera were isolated and identified from the above mentioned sites. Cyanobacteria (Cyanophyceae members) were most dominant (80-95%) on many occasions. Algae present in dust were found almost in equal numbers, both qualitatively and quantitatively, both indoors and outdoors. In round-the-clock investigations more number of genera were isolated from noon to midnight. Aphanothece and Phormidium were found in almost all the samples, irrespective of the time of the sample collected. From these investigations it is observed that there is no aerial micro-algae free season, but the incidence and abundance may vary from season to season.