Intranasal steroids are highly effective drugs for treating patients with allergic rhinitis. First-line use of intranasal steroids is becoming increasingly common, and intranasal steroids can be used alone or in combination with other therapies to achieve optimal improvement in rhinitis symptoms. The major adverse effect of intranasal steroids is local irritation. This article reviews the mechanism of action of corticosteroids, the effects of intranasal steroids on chemical mediators of inflammation, and the risks and benefits associated with their use.