Three men armed with locally manufactured guns attacked the Adaklu-Abuadi stone quarry, near Ho, on Saturday.
The robbers shot and killed one worker at the site, before bolting with a safe containing GHS40,000.
They also took away an unspecified amount of assorted foreign currencies.
The police gave the name of the deceased as Sampson Deklu, 31.
Assistant Superintendent of Police ( ASP) Alex Adade Yeboah, Ho Municipal Police Commander, confirmed the incident to Ghanaian Times.
He said the assailants, who wore face masks, also injured Kodzo Yao, 24, Emmanuel Nartey, 40, Alex Agovor Kwami, 48, and Kwaku Segbedzi, 29, all workers, at the quarry during the raid.
ASP Yeboah said that the police, upon receiving a report on the incident, acted swiftly and proceeded to the quarry where they saw the body of the deceased lying in a pool of blood in a supine position.
He said the body has been taken to the Ho Teaching Hospital for autopsy, and two spent bullet shells had been retrieved from the scene.
ASP Yeboah appealed to the public to give information to the police to enable them to arrest suspects.
No one was arrested in connection with the incident at the time of filing this report.