Researchers recruited walkers on two Dunedin hillside footpaths in 2008 for a randomised controlled trial.
Half of the pedestrians were given socks to put over their footwear, while those without socks over their shoes were the control group.
The study found pedestrians with the socks found the slopes less slippery and had increased confidence.
"Wearing socks over normal footwear was associated with a statistically significant improvement in traction," the researchers said in an article published today in the New Zealand Medical Journal.
The practice of wearing socks over shoes is popular in the city and advocated by Dunedin City Council as a way to avoid slips on icy mornings, but has never been scientifically proven.