The teeth and gingivae of 20 children with asthma aged up to 6 years who had been taking syrup medicines regularly for at least six months were compared with those of a control group of 79 children of similar ages. Dental disease was assessed by measuring dental plaque(plaque index) and gingivitis(gingival index). The results of this study show that long-term administration of syrup medicine ketotifen sweetened with glucose increase the plaque index and gingival index in children who had primary dentition. But there was no significant difference between the two groups. By increasing the intake duration of syrup, both indices were increased.