A non-SARS coronavirus multiplex nucleic acid assay is a multiplex in vitro diagnostic test for the simultaneous qualitative detection and discrimination of coronavirus 229E, coronavirus NL63, coronavirus HKU1 and Coronavirus OC43 nucleic acids isolated and purified from human respiratory specimens obtained from individuals exhibiting signs and symptoms of respiratory tract infections or viral culture. The detection and discrimination of human non-SARS coronavirus nucleic acids from symptomatic patients aid in the diagnosis of human respiratory tract non-SARS coronavirus infections if used in conjunction with other clinical and laboratory findings.