Allergic Rhinitis (AR) and Asthma are highly prevalent diseases. Cysteinyl leukotrienes, key drivers of symptom in both asthma and early and late AR response, are not blocked by steroids or antihistamines. Montelukast has proven to be efficacious in the treatment of both AR and asthma. Patients and method: the auto controlled descriptive follow-up study on 50 patients aged 18-60 years old with allergic asthma. Results: after 12 months of treatment, the clinical symptoms were markedly improved: there is significant progress for the symptoms of asthma at 81.5 percent and 83.1 percent on the development of symptoms at night. Patients with significant progress with AR symptoms (sneezing 82,5 percent, rhinorrhea 92,5 percent, blocked nose 85 percent). Asthma drugs and AR drugs are also used reducing (82,3 percent). Conclusion: Montelukast 10mg is an effective and safe treatment for allergic asthma patients. All patients had the intention to continue using Montelukast. Montelukast is well tolerated, side effects are mild (appeared in 01 patients).