Acute bacterial rhinosinusitis is a common infection resulting in substantial morbidity. Cefdinir, an oral cephalosporin, has extended-spectrum, bactericidal activity against common acute bacterial rhinosinusitis pathogens, including Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Cefdinir shows rapid oral absorption and good respiratory tissue penetration, and may be administered once daily. In randomised clinical trials, cefdinir showed efficacy similar to that of other recommended regimens in the treatment of acute bacterial rhinosinusitis, namely amoxicillin/clavulanate and levofloxacin. Cefdinir is well tolerated and has shown a low propensity to suppress the normal commensal flora. Cefdinir oral suspension is rated highly by children in terms of its taste and smell. As the only once-daily beta-lactam currently recommended by acute bacterial rhinosinusitis guidelines (for first-line use in patients with mild acute bacterial rhinosinusitis and no recent antibacterial use), cefdinir offers a convenient and attractive treatment option.