The exact aetiology of nasal polyposis is not yet established although it is believed that allergic, infectious, mechanical, immunological and biochemical factors may be involved. Using the technique of polymerase chain reaction, this study assesses the role of human adenovirus, metapneumovirus, coronavirus, parainfluenza virus types 1, 2 and 3, influenza A and B virus, respiratory syncytial virus A and B and rhinovirus A and B in the formation of nasal polyps. The authors used the method of polymerase chain reaction based on nucleic acid isolation, reverse transcription, polymerase chain reaction amplification of target DNA and DNA detection with agarose gel electrophoresis. There were 30 patients with nasal polyps, 22 men and eight women, and a control group of 20 healthy patients. Nasal polyposis was diagnosed histopathologically. Tissue examination by agarose gel electrophoresis identified human coronavirus and rhinovirus in one of the patients in the control group. Another patient in this group had human respiratory syncytial virus. Influenza B virus was identified in one of the nasal polyp patients along with human coronavirus in another in this group. There was no statistically significant relationship between nasal polyposis and respiratory viruses. The study therefore does not support viral aetiology in the formation of nasal polyps. References have been made to past studies which showed a high prevalence of EBV in normal nasal pharyngeal mucus but not in nasal polyps. Therefore its role in nasal polyposis is doubtful which agrees with this study. The aetiology of this common condition therefore still remains uncertain.