With rising rates of allergy, and a lack of detailed data about airborne allergen sensitisation in Australian children, we sought to examine patterns of aero-allergen sensitisation in atopic children and adolescents in Sydney, NSW. A retrospective cross-sectional study of atopic children who underwent aeroallergen allergy skin testing (SPT) at Children’s Hospital at Westmead between May 2013 and December 2014 was undertaken. Children were eligible if they had SPT to nine commercial aeroallergens (rye, bahia, bermuda, english plantain (EP), D. pteronyssinus (HDM), D. farinae (HDM), cat, dog and alternaria), and were atopic to at least one (≥3 mm). 517 children were identified, 75% were male, with a median age of 9.2 years (IQR 6.3–11.4). The most common sensitisation was to HDM (90%), with rye grass (45%) the most common grass. 31% had sensitisation to alternaria; 26% to cat and 17% to dog. 78% of children were polysensitised (>1 allergen), and amongst the monosensitised children most were positive to HDM (87%). The largest proportion of children were senisitised to 2–3 allergens, with the number of aeroallergens increasing with age (Pr>ChiSq <0.0001). The proportion of grass sensitisation increased with age. Preschool children (age<6) were predominantly sensitised to HDM (88%), with lower rates of grass sensitisation (rye 28%, bahia 16%, bermuda 10%, EP 22%), compared with the teenage group who had similar rates of HDM sensitisation, but higher rates of grass positivity (rye 52%, bahia 36%, bermuda 27%, EP 43%). Animal dander sensitsation appeared to be evenly distribution across the age groups. Most children (58%) had sensitisation to both indoor and outdoor allergens; 33% to only indoor and 7% to only outdoor allergens. This pattern was similar across the age groups. Explorative geoanalysis of sensitisation patterns suggested a geographic variance in the purely grass sensitised children to North-West Sydney. In comparison, the distribution of monosensitised HDM and polysensitised children mirrored the geo-location of the whole cohort. We have observed patterns of aeroallergen sensitisation in our cohort, with HDM being the predominant allergen in children, and polysenstisation increasing with age. Location may be a driver of aero-allergen sensitisation. It would be useful to further confirm these associations with prospective population cohort studies.