The large and growing number of viral and bacterial pathogens responsible for respiratory infections poses a challenge for laboratories seeking to provide rapid and comprehensive pathogen identification. We evaluated a novel application of the TaqMan low-density array (TLDA) cards for real-time PCR detection of 21 respiratory-pathogen targets. The performance of the TLDA was compared to that of individual real-time PCR (IRTP) assays with the same primers and probes using (i) nucleic acids extracted from the 21 pathogen strains and 66 closely related viruses and bacteria and (ii) 292 clinical respiratory specimens. With spiked samples, TLDA cards were about 10-fold less sensitive than IRTP assays. By using 292 clinical specimens to generate 2,238 paired individual assays, the TLDA card exhibited 89% sensitivity (95% confidence interval [CI], 86 to 92%; range per target, 47 to 100%) and 98% specificity (95% CI, 97 to 99%; range per target, 85 to 100%) overall compared to IRTP assays as the gold standard with a threshold cycle (C(T)) cutoff of 43. The TLDA card approach offers promise for rapid and simultaneous identification of multiple respiratory pathogens for outbreak investigations and disease surveillance.