The aim of this study was to investigate the effects of leukotriene receptor antagonists (LTRAs) on the premenstrual exacerbation of asthma (PMA). Twenty-four female patients with mild asthma were enrolled in the study. Patients were followed for three menstrual cycles and separated into two groups based on whether they exhibit premenstrual worsening of asthma symptoms (n = 11) or not (n = 13). During the first month all were treated with only inhaled steroids (IS) (run-in period); during the second month they received IS plus placebo; and during the third month they were given IS plus montelukast. Furthermore, they were advised to use beta(2)-agonists as needed. Peak expiratory flow rate (PEFR) and symptom scores were recorded during the 3 months. Pulmonary function tests (PFT) and the levels of oestrogen, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured a week before the beginning of the menstrual period. At the end of the 3-month period, it was observed that following therapy with montelukast, the patients with PMA showed significant improvement in PEFR variability and symptom scores when compared with the placebo group. Baseline FSH levels were higher, but FSH and other hormone levels and PFTs did not change in these groups. However, in the group without PMA there was no difference between the montelukast or placebo groups in PEFR variability, symptom scores, PFTs, and hormone levels. Based on the data in hand, it could be stated that LTRAs have ensured the control of symptoms and improved PEFR variability in patients with PMA by suppressing inflammation. We are of the view that LTRAs would be a right choice in the treatment of patients with PMA.