Rising demands for repetitive SARS-CoV-2 screens and mass testing necessitate additional test strategies . Saliva may serve as an alternative to nasopharyngeal swab (NPS) as its collection is simple, non-invasive and amenable for mass- and home testing, but its rigorous validation, particularly in children, is missing . We conducted a large-scale head-to-head comparison of SARS-CoV-2 detection by RT-PCR in saliva and NPS of 1270 adults and children reporting to outpatient test centers and an emergency unit . In total, 273 individuals were tested positive for SARS-CoV-2 in either NPS or saliva . SARS-CoV-2 RT-PCR results in the two specimens showed a high agreement (overall percent agreement = 97.8 %). Despite lower viral loads in the saliva of both adults and children, detection of SARS-CoV-2 in saliva fared well compared to NPS (positive percent agreement = 92.5 %). Importantly, in children, SARS-CoV-2 infections were more often detected in saliva than NPS (positive predictive value = 84.8 %), underlining that NPS sampling in children can be challenging . The comprehensive parallel analysis reported here establishes saliva as a generally reliable specimen for the detection of SARS-CoV-2, with particular advantages for testing children, that is readily applicable to increase and facilitate repetitive and mass testing in adults and children.