11,119 patients with scarlet fever admitted in the last sixteen years, from 1973 to 1988, to Sapporo City General Hospital, were studied statistically on symptoms and laboratory findings. The results were summarized as follows: 1. Annual number of patients have reduced suddenly since 1981, and become zero in 1989. The patients increased in number during the winter season. Eighty two percent of the cases were between 3 and 8 years of age, and the average age was 5.8 year-old. 2. Cases of above-38 degrees C temperature were seen in about 81.4%, and from 2 to 5 days-duration of temperature were seen in 86.6% of the patients in the year 1976. Cases of above-moderate rash were observed in 68.2%, sever redness of throat in 29.9%, strawberry tongue in 86.3% and angular stomatitis in 37.7% of the patients. In recent statistical analysis (1982-1988), we found, however, a tendency that patients having stronger symptoms were being introduced to our hospital. 3. The higher rates of cases showing elevated ASD titer were seen in the elder patients and in the winter. C-reactive protein (CRP) titers were mostly in the range of (-) to (greater than or equal to 6+), having 2.4 + on an average. 4. Patients who developed into overt nephritis were not seen. Cases of microscopic hematuria (greater than or equal to 3 red cells/f in urine sediments), however, were observed in 1.1% (125/11,119). Sever complications were hardly seen. 5. Reappearance of beta-hemolytic streptococci (on a week after discharge) were found in 3.1% (241/7,877). 6. Reinfection or relapse cases of scarlet fever were found in 6.7% (642/9,585).(ABSTRACT TRUNCATED AT 250 WORDS)