Background: Staphylococcus aureus (SA) colonization is frequent in patients with perennial allergic rhinitis (PAR). Mupirocin has well-recognized antistaphylococcal activity, and its nasal formulation is approved for the eradication of SA nasal colonization. Objective: To investigate the frequency of SA nasal carriage, its possible influence on AR severity, and nasal mupirocin's role on AR clinical severity. Methods: Sixty patients, aged 5 to 60 years, with AR were included, and 55 healthy individuals served as a control group. Nasal smear specimens were drawn from both nares. A skin prick test to inhalational allergens and a score-graded clinical evaluation of AR were performed. Carriers of SA were treated with topical nasal mupirocin. Results: The SA carrier (SAC) state was found in 23 (38%) of the patients with AR and in 8 (15%) of the healthy controls (P = .004). Comparing SACs with AR SA noncarriers, nasal symptom scores (SSs) tended to be higher in the SAC group (mean [SD], 11.09 [2.16] vs 8.86 [1.43]; P < .005). Treatment with topical nasal mupirocin diminished the SAC state to 10% (P = .009) but did not change AR clinical severity, as assessed by the SS. Conclusions: In patients with PAR, the SAC state is more prevalent compared with the healthy population. Topical nasal mupirocin reduces the SAC state but fails to clinically improve PAR, as assessed by the SS.