Emergency services were called to North Island Mussel Processors in Greerton after a worker got his hand trapped in a piece of machinery.
A fire service spokesman said firefighters were called to the site in Glenlyon Ave just after 1pm yesterday.
Greerton fire service Station Officer Paul Van Kol said on arrival the man had already been freed from the machine and he was sitting in the first-aid room with his hand bandaged.
A St John Ambulance was already in attendance, he said.
The man was treated for minor injuries at Tauranga Hospital and discharged.