Omalizumab is a humanized monoclonal anti-IgE antibody, which is widely used for patients with severe uncontrolled asthma. Treatment with omalizumab is known to decrease the number of exacerbations and GETE score (Global Evaluation of Treatment Effectiveness) - but little is known about which patients benefit the most. Moreover, the time to discontinuation of the treatment with omalizumab has yet to be investigated. In this real-life study on a Danish population we explore these important issues. In a retrospective real-life study, 54 patients treated with omalizumab at a specialized outpatient asthma clinic were included. Change in GETE score, time to discontinuation of treatment and associated risk factors were analysed. As a result of omalizumab treatment, most patients improved in GETE score from poor/worsening to excellent. Women were treated for a median time of 31 months (95% CI: 4.6-57.4) and approximately 50% of patients discontinued treatment after 500 days whilst, for men, 50% discontinued treatment after 1500 days. Eosinophil count above 300 cells/μL at treatment initiation was positively related to the discontinuation of omalizumab (HR 4.3 95%CI (1.22-15.28) p = 0.023). In conclusion, female gender and an eosinophil count above 300 cells/μL may predict a better treatment response, leading to a shorter treatment time than the current guideline recommendation of maximum 48 months. Additionally, the GETE score improves with omalizumab. More real-life studies are needed to determine which patients will benefit the most from the treatment.