The medical community has neglected olfactory dysfunction for a long time. However, over the last two decades, remarkable progress has been made in terms of understanding the sense of smell and both the assessment and diagnosis of olfactory dysfunction. Currently, there are only a few validated olfactory tests. The most commonly used one is the University of Pennsylvania Smell Identification Test. Owing to its cultural biases, this test is mostly used in the United States. "Sniffin' Sticks" are one of the first European tests to be widely. used. Since their development in 1996, they have been applied in numerous studies and have found increasing use in otolaryngology clinics. The goal of this article is to present Sniffin' Sticks and to provide a review of clinical olfactory research during recent years.