We report the characteristics of 45 Epstein-Barr virus (EBV)-infected patients visiting our hospital from 1989 to 1991 in comparison with 102 patients seen from 1981 to 1988. Cases of infectious mononucleosis (IM) increased especially in patients over 30 years old. They tended to have nonspecific symptoms and signs for IM such as general fatigue. Immunologically showed twice higher positivity for anti-EBV VCA-IgM antibody in the recent 3 years when compared to the previous 8 years. The patients with anti-EBNA antibody decreased in the recent 3 years. This may be due to early diagnosis as IM. EBV also causes atypical diseases. non-IM in this report, including hematological or neurological disorders. We indicated here the increased number and advanced age of patients with IM and early diagnosis as IM in the recent 3 years compared to the previous 8 years.