The aim of this study was to evaluate the effect of bronchial asthma on menstrual cycle. The study population consisted of 111 girls aged 8-17 years (58 girls with bronchial asthma and 53 healthy girls) of the mean age of 13.17+/-2.74 years. The age at menarche and menstrual cycle parameters were analyzed. Asthmatic girls started to menstruate earlier than healthy girls (P=0.0004). The severity of bronchial asthma (P=0.0096) correlated with the age at menarche. Irregular menstrual cycles were found in 50.0% of asthmatic girls and 27.8% of control group (P=0.03). Algomenorrhea was observed in 68.0% of girls with asthma and in 80.6% of healthy ones (P=0.013). We conclude that bronchial asthma increases the risk of irregular menstrual cycles prevalence but decreases the frequency of algomenorrhea among girls. The age at menarche is accelerated in bronchial asthma.