Summary Background Poor adherence to asthma treatment is a well-recognised challenge and is associated with increased morbidity, mortality and consumption of health care resources. This study examined the impact of receiving a daily text message reminder on one's cell phone on adherence to asthma treatment. Methods A total of 26 subjects aged 18–45 years, with a clinical history of asthma and a positive methacholine challenge test (PD 20 ≤ 4 μmol) were randomised to receive, or to not receive, a daily short message service (SMS) reminder on their cell phone to take their anti-asthmatic medication. Inhaled corticosteroids to last for eight weeks and a prescription for four additional weeks were given to the subjects. The primary outcome was adherence to asthma treatment. Secondary outcomes were reimbursement of asthma medication, and change in exhaled nitric oxide levels, lung function, and airway responsiveness. Results The absolute difference in mean adherence rate between the two groups after 12 weeks was 17.8%, 95% CI (3.2–32.3%), p = 0.019. No significant differences were observed between the two randomisation groups for the secondary outcomes. Conclusion Daily text message reminders are already after a short period of observation associated with increased adherence to anti-asthmatic medication.