Olfactory dysfunction is a common symptom in patients with inflammation of the nasal mucosa. Among numerous drugs, so far only the use of steroids has been shown to have a positive effect on olfactory function. Therefore the aim of the present study was to investigate whether patients with sinonasal disease would benefit in terms of olfactory function from oral treatment with a herbal drug (combination of primrose, gentian root, vervain, elder flowers, and sorrel: Sinupret(r)) which is commonly used in sinusitis. Olfactory function was tested using a standardised olfactory test kit (`sniffin` sticks`). The drug was applied in a double-blind fashion: after an initial therapy of 7 days of oral prednisolone for all participants with a sinonasal olfactory disease, participants were divided into a placebo- and a verum-group; tests were performed before and after treatment over a 2 months period. Statistical analysis did not reveal any major differences in olfactory function in relation to treatment. Considering that its benefit for the inflammatory component of sinusitis has been shown, the herbal drug may exhibit positive effects on olfactory function in a different setting, e.g., when applied without preceding administration of prednisolone, or when used in patients with certain degrees of rhinosinusitis.