The Korean Health and Medical Workers' Union (KHMU) said it reached an agreement with the government in their last-ditch talks held the day before.
The decision to call off the planned strike came after midnight as union members took time to discuss the tentative agreement with the government.
The sides were said to have agreed on the need to avoid any vacuum in medical services amid the COVID-19 pandemic.
Details of the agreement were not immediately known.
Nearly 56,000 nurses, medical technologists and other health workers were expected to take part in the walkout if held, according to KHMU, which represents some 80,000 medical professionals. (Yonhap)