Fire engines from across Dunedin raced to Port Chalmers after acid spilled on a vessel berthed at the wharf.
Emergency services were alerted about 5.30pm, after a log fell on two drums of hydrochloric acid, a Fire and Emergency New Zealand spokeswoman said.
The drums had then burst and their contents were spilt on the ship’s deck.
Firefighters used an absorbent to clean up the spill and left the scene about 11.34pm.
No-one was believed to have been injured during the incident.
The spokeswoman said appliances were dispatched to the incident from the Port Chalmers, Ravensbourne, Dunedin city, Willowbank and Roslyn fire stations.
About 220 litres of the acid was said to have spilt on the deck during the incident.