Background Recently, respiratory diseases which have very high rates of infection and morbidity are ocurring more frequently because of economic and environmental changes in our society. There are many difficulties in confirmatory diagnosis and treatment of the causative agents, because respiratory diseases can be commonly induced by bacteria and viruses simultaneously Viral respiratory diseases are caused by diverse viruses such as Influenza virus, Adenovirus, Enterovirus, Parainfluenza virus, Respiratory Syncytial virus, etc. Therefore, a correct diagnosis and knowledge of outbreak patterns, through the isolation of viral respiratory disease agents are significant. Also, monitoring and prevention for the diseases are required through antigenicity range analysis for domestic prevalent strains. Methods We isolated and examined Influenza and respiratory viruses from the respiratory tract throat swab specimens from patients hospitalized in Busan from January to December in 2004, by cell cultivation and RT-PCR method. Results In 182 cases(9.8%) of 1,869 respiratory specimens, 119 cases of Influenza A/Fusian/412/2002(H3N2), 35 cases of Influenza B/Hongkong/330/2001 and Influenza B/Sichuam/379/99, 3 cases of Adenovirus 1, 8 cases of 3, one case of 4, one case of Parainfluenza 2, one case of Echovirus 3, one of 6, one of 30, 3 cases of Coxsackievirus B1, 4 cases of B2, 5 cases of Poliovirus were detected. The rates of Influenza detection were high from February to April, and other respiratory viruses showed a high rate in July and August. Most respiratory viruses were detected from children under 10 years of age, and a similar outbreak distribution was indicated in other age groups. While females showed a slightly higher rate of detection than males for Influenza viruses, the ratio of males and females for other respiratory viruses was 2:1, which indicated a higher rate in men. Conclusions Respiratory viruses are quickly disseminated and transmitted from person to person and have frequent mutations, so it is difficult to predict the practical vaccination effect. Therefore, the result of the curative research using Tamiflu(Oseltamivir), Influenza medication, on Influenza patients have revealed that it can reduce the fever period and related complications. In conclusion, Influenza resistance strain detection work has to be continued, and nationwide surveillance of causative respiratory virus detection and epidemiological investigation are vital. Moreover, there is little data for diverse Enteroviruses detected from respiratory specimens, so further studies should be performed.