Last month, doctors in the region suspended a strike after talks between the county government and union officials.
The county and the union agreed that more than 62 doctors be issued with promotion letters by August 24, 2020.
Doctors in Nyamira are planning to down their tools next week if the county government does not fulfil their demand for promotions.
The Kenya Medical Practitioners Pharmacists and Dentists’ Union (KMPDU) Nyanza branch has issued a seven-day strike notice after the county government failed to implement a deal reached between the union and the devolved unit last month.