Three elderly patients were consecutively found to harbor or to become infected with intermediate-level penicillin-resistant Streptococcus pneumoniae in a hospital respiratory ward. All the isolates from the respective patients produced mucoid-type colonies on sheep blood agar plates and were found to have an identical antibiogram, indicating that those were resistant against erythromycin, clarithromycin, clindamycin and minocycline. Pulse-field gel electrophoresis of genomic DNA digested Sma I and Apa I demonstrated homology among the isolates, which may suggest person-to-person spread in a hospital setting. With this, it is an urgent to establish the institution-based infection control precautions against S. pneumoniae.