The effect of 60 mg twice-daily fexofenadine HCl on health-related quality of life and productivity at work, in the classroom, and during daily activities in patients with moderate to severe chronic idiopathic urticaria symptoms was studied in two identical, 4-week, placebo-controlled, multicenter clinical trials. Patients self-administered the Dermatology Life Quality Index (score, 0-30) and the Work Productivity and Activity Impairment instrument (0%-100%). In both trials, improvements in Dermatology Life Quality Index scores in fexofenadine-treated patients (N = 169) were statistically significant compared with placebo (P < or =.0002). Similarly, improvements in productivity scores with fexofenadine 60 mg twice daily were statistically superior to placebo at work (n = 120, P < or =.0152) and in performance of daily activities (n = 166, P < or =.0002). There was a trend toward improved classroom productivity (n = 26) with fexofenadine. We conclude fexofenadine 60 mg twice daily improves health-related quality of life, increases work productivity, and improves performance of daily activities in patients with moderate to severe chronic idiopathic urticaria.