Allergic rhinitis (AR) is a common chronic condition in children and may impact a child's quality of life. Increasing treatment compliance may improve quality of life. An oral suspension of fexofenadine hydrochloride (HCl) has been developed to ease administration to children and may, therefore, improve treatment compliance. The purpose of this study was to assess the pharmacokinetic behavior, safety, and tolerability of a single dose of fexofenadine HCl oral suspension administered to children aged 2-5 years with allergic rhinitis. Children (aged 2-5 years) with AR were recruited in a multicenter, open-label, single-dose study. Fexofenadine HCl (30 mg) was administered as a 6-mg/mL suspension (5 mL). Plasma samples were collected up to 24 hours postdose. Adverse events (AEs); electrocardiograms (ECGs); vital signs; and clinical laboratory tests for hematology, blood chemistry, and urinalysis were analyzed to evaluate safety and tolerability. Fifty subjects completed the study. Mean maximum plasma concentration of fexofenadine was 224 ng/mL, and mean area under the plasma concentration curve was 898 ng . hour/mL. Treatment-emergent AEs were mild in intensity and reported in a total of seven subjects. No trends or clinically meaningful changes in mean ECG, vital sign, or clinical laboratory test data occurred during the study. In children aged 2-5 years, the exposure after a 30-mg dose of fexofenadine HCl suspension was similar to the exposures previously seen after a 30- and 60-mg dose of fexofenadine HCl in children aged 6-11 years and in adults, respectively. The suspension was also well tolerated.