Unidentified assailants riding a motorcycle opened fire on a checkpost in the Chakki Shahwani area, killing one policeman on the spot and wounding two others, police sources said.
The injured were rushed to the hospital where one of the police officers succumbed to his wounds.
The gunmen fled following the attack, the sources said, adding that the shooting appeared to be an incident of targeted killing.
Saryab road is considered to be one of the sensitive areas of Quetta. Militants have been targeting security forces in the area for almost a decade.
Balochistan has experienced incident violence and targeted killings for over a decade.