Introduction: To examine trends in respiratory diseases other than infectious diseases is important for public health issue during coronavirus disease 2019 (COVID-19) pandemic. This study aimed to examine the trends in patient consultations for asthma and Chronic Obstructive Pulmonary Disease (COPD) at Show a University Hospital in Japan during the COVID-19 declaration of the state of emergency. Methods: This study designed as a retrospective and descriptive study. Subjects were 6,483 patients who had received medical treatment at Show a University Hospital and were diagnosed asthma or COPD from 2017 to 2020. To examine the impact of the COVID-19 declaration of the state of emergency, the number visits to hospital by asthma were summarised from January to September, for each year. Results: Compared to the average of the previous 3 years, a comparison of the three periods (before, during and after the COVID-19 declaration of the state of emergency) showed a V-shaped curve in 2020, with a large drop in the number of asthma and COPD patients during the COVID-19 declaration of the state of emergency. The number of patients recovered after the COVID-19 declaration of the state of emergency was lifted, but not returned to the pre-declaration level. Conclusions: This study showed a long-term decrease in asthma and COPD patients visits to Show a University Hospital since the beginning of the COVID-19 pandemic compared to the previous 3 years. It is also possible that medical care that would have been available may not have been provided due to the COVID-19 declaration of the state of emergency, so it is necessary to follow up patients while keeping a close eye on measures other than infectious diseases. Keywords: asthma; COPD; the COVID-19 declaration of the state of emergency; infection control; japanese.