We present a case of pansinusitis with orbital involvement associated with an allergic response to the fungus Curvularia (Cochliobolus) lunata. Key elements to the diagnosis included a predominant eosinophilic response of the sinus mucosa, the presence of a characteristic mucoid exudate containing fungal hyphae, peripheral blood eosinophilia, serum precipitins against C lunata, elevated serum total and Curvularia-specific IgE and IgG concentrations, and immediate cutaneous reactivity to C lunata antigen. This report suggests that an exaggerated allergic response should be considered in the pathogenesis of pansinusitis. The presence of fungal hyphae in sinus mucosal specimens should alert the physician to the possibility of this disease. Sinus fungal cultures, as well as thorough immunologic evaluation, of such patients is recommended.