The purpose of this article is to determine allergic rhinitis and age as potential risk factors for the development of orbital complications of acute rhinosinusitis in children. One hundred two children presenting with orbital swelling were investigated by computed tomography (CT) of the paranasal sinuses and the orbit as well as for underlying allergic rhinitis. Sixty (58.8%) patients had orbital complications of clinical and radiological acute rhinosinusitis. They were grouped accordingly: preseptal cellulitis (n = 24), periostitis (n = 10), and subperiosteal abscess (n = 26). No abscess within the orbit or cavernous sinus thrombosis was found. Thirty-four (56.7%) of the 60 patients underwent allergy investigation. Allergic rhinitis was found in 9 (64.3%) of 14 children with preseptal cellulitis, in 1 (25%) out of 4 children with periostitis, and in 13 (76.5%) out of 17 children with subperiosteal abscess. The prevalence of allergic rhinitis was significantly higher in patients presenting in pollen season from February to August (17:4) than in patients presenting in the period between September and January (6:7). Thus, allergic rhinitis may be a cofactor in the pathogenesis of orbital complications of acute rhinosinusitis. According to our study population, age only influences the type of orbital complication of acute rhinosinusitis in the sense that older children are more likely to develop subperiosteal abscess, whereas younger children develop preseptal cellulitis.