Background : There have been very few studies conducted on the number and type of microorganisms that remain on the ring finger after handwashing. This study was performed to investigate whether there were changes and differences in the type and number of microorganisms on the ring finger before and after handwashing. Method : The subjects of the study were 15 MICU and SICU staff nurses who were wearing rings. I swabbed two different fingers of the same hand with cotton balls. One finger which had a ring and the other with no ring. I swabbed the fingers of each subject three times(before handwashing, after handwashing with soap, and after handwashing with bethadine solution). After storing them for 48 hours in an incubator, I sent them to the laboratory and recorded the culture results. Results : There was no difference in the type of microorganism, but a major difference in the number of the microorganisms that existed on the finger ring. The results showed that there were much more microorganisms on the ring fingers than on the fingers that did not have rings both before and after handwashing. This tendency was consistent regardless of the handwashing agent. I therefore recommend that all nursing staff who work in general nursing units, as well as nurses who work in the ICU, remove their rings when taking care of the patients.