In a clinical trial to investigate the effect of violet syrup on cough relief in children with intermittent asthma, 182 children aged 2 to 12 years in two parallel groups received violet syrup and placebo along with the common beta-receptor agonist (salbutamol). During the treatment period, more than 50% reduction in cough (P.Value = 0.001) and 100% inhibition of cough (P.Value <0.001) in the violet syrup group were significantly greater than the placebo group. The effect of the drug did not differ between boys and girls. This study showed that co-administration of violet syrup with salbutamol (a beta-2-adrenoceptor agonist) is effective in controlling cough in patients with intermittent asthma.