We report three cases of acute conjunctivitis due to different types of human adenovirus (HAdV) in medical workers. Case 1: A 37-year-old man had epidemic keratoconjunctivitis and urethritis caused by human adenovirus type 37 (HAdV-37). Case 2: A 27-year-old woman had acute conjunctivitis due to human adenovirus type 15 (HAdV-15), Case 3:A 32-year-old woman had acute follicular conjunctivitis leading to a serotype of human adenovirus-53 serotype (HAdV-53). Note that HAdV-37 infection may cause keratoconjunctrivitis and urethritis. HAdV-15, -37, and -53 are important causative agents of nosocomial outbreak, and the application of a rapid diagnostic kit or PCR to a rapid diagnosis and proper infection-control measures can significantly reduce infection spread.