The suspension bridge over the Manuherikia River, built in 1877, is still used as a footbridge.
Central Otago District Council's roading manager Julie Muir said work would begin early in June on replacing 13 transoms (the beams under the walkway), some handrail balusters and some of the decking.
The project will cost about $44,000 and take three weeks to complete.
All of the decking will be screwed down rather than nailed, to make it more secure.
The nails used to attach the existing decking had tended to work loose.
"So when the work's finished, the Shaky Bridge will still be shaky but more safely shaky," Ms Muir said.
The bridge was opened for light traffic in 1879 at a cost of 974 but the nearby road-rail traffic bridge, opened in 1906, became more popular.
The Shaky Bridge slowly deteriorated and was eventually closed, being sold for £1.
It was handed back to the local authorities in 1951.
A committee raised $1800 to restore the bridge and opened it in 1952 as a footbridge, dedicated to the town's pioneers.
Ms Muir said the maintenance work would not alter the character of the structure.
"We're very conscious that it's a historic bridge, so the timber will match what's already there and it will look the same."
The bridge will close immediately after Queen's Birthday weekend and pedestrians and bikers will have to use the pedestrian walkway next to the road-rail bridge to get across the Manuherikia River until work is complete.
