The shooting occurred on January 29 in the village of Parmolo in Swabi district, Khyber Pakhtunkhwa Province.
The two polio workers were participating in a polio immunization campaign in the area, local police told RFE/RL.
There was no immediate claim of responsibility.
In the past decade, Taliban militants have killed scores of health workers and police guarding them because they believe anti-polio vaccination campaigns are intended to sterilize Pakistani children.
Pakistan, where polio is still endemic, regularly carries out anti-polio drives.