Intranasal steroids are widely used in the treatment of allergic rhinitis. Whether or not the addition of montelukast helps was assessed in this study. This was a single centre prospective randomised double-blind placebo-controlled trial of two groups of patients, one receiving intranasal steroids with a placebo and the other intranasal steroids with montelukast. Symptom scores and quality of life questionnaires were obtained in the first visit when the treatment was started. All patients had moderate to severe allergic rhinitis and therefore sleep disturbance was also taken into account. Identical recordings were taken at four and eight weeks after starting the treatment. Patient compliance was studied and results were subjected to statistical analysis. At the end of one month the mean scores for daytime nasal and nocturnal symptoms, but not daytime eye symptoms, were significantly lower in the montelukast group compared to the placebo group. All symptom scores improved significantly at two months, but the improvement was significantly greater in the montelukast group. The quality of life score was improved in the montelukast group and the difference compared with the placebo group was statistically significant. A record was also made of breakthrough symptoms and requirement of loratidine; this was much lower in the montelukast group. The authors are aware that this study is limited due to lack of objective measures such as rhinomanometry. The results of this study quite convincingly suggest that addition of montelukast in patients with moderate to severe allergic rhinitis is helpful in reducing symptoms and improving quality of life. The study is well structured and suggests a simple method to improve the management of allergic rhinitis.