Purpose: This study was to identify the types and characteristics of health problems of middle school students in Gangwondo. Methods: The subjects of the study were 11 middle schools from 47 schools with nurse teachers in Gangwondo. The anecdotal records of the school health clinics were collected from March to December in 1998 with the agreement of nurse teachers of the schools. Results: 71.0% of the middle students visited the school health care clinics once or more than once. The mean frequency of health problems was 2.03 times per one year. The rate of health problems did not show any statistical differences by sex, school location, age, the day of the week and weather. However, there were statistical differences of the rate by month. The highest rate was showed in September, followed by June and April (F=2.52, p=0.01). Health problems were classified into 11 types. Gastrointestinal illness showed the largest proportion (60.6%). The oral illness showed statistical differences among the location of school, between municipal and rural area (t=-2.97, p=0.016). There were 411 types of signs and symptoms recorded. Among them, headache was showed the highest proportion with 2,122 cases (11.2%). Conclusion : The incidence rate of health problems was higher than that of earlier studies. It showed that the incidence rates and the types of diseasps in middle school students were different by school locations, characteristics of students, and months. To improve the qualities of primary cares in school health services, the reformed and unified anecdotal record system and the standardized guidelines for primary care are necessary.