CDC scientists have developed a real-time PCR assay for diagnosing pneumococcal disease using amplification of the bacterial gene encoding pneumococcal surface adhesin A (PsaA). Pneumococcal isolation and identification is often complicated by 1) antimicrobial suppression of growth in culture and 2) contamination by normal flora alpha-streptococci. Further, pneumococcal detection by culture and serological methods can be time-consuming, relatively expensive, laborious and, ultimately, indeterminate. Sensitive and specific assays that can be completed quickly in the clinical laboratory are essential for early diagnosis and effective therapy. This RT-PCR assay provides a tool for quick and accurate diagnosis by physicians and health care technicians and may be useful in evaluating the efficacy of novel pneumococcal vaccines and therapeutics.