The implementation of PCV vaccination programs has begun in many Asian countries over the past decade. However, studies examining invasive pneumococcal disease and the benefits of PCV vaccination programs remains limited. This study aims to determine the characteristics of patients with invasive pneumococcal disease and the effect of PCV vaccination. This research is a descriptive observational study and the method used for this study was prospective data collection from inpatients in regular wards and ICUs with pneumococcal pneumonia and invasive pneumococcal disease in 2023 and 2024. The invasive pneumococcal disease included in this study refers to patients with positive pneumococcal culture results detected in blood or pleural fluid cultures. Meanwhile, the pneumococcal pneumonia cases studied were those with positive culture results for pneumococci detected in sputum culture. This research was conducted at Persahabatan Hospital, following approval from the hospital’s Ethics Committee and with sponsorship from Pfizer.