Shops and bars on Elvet Bridge in Durham said Lumiere cost them thousands of pounds in trade, despite attracting 175,000 people to the city over four days.
The light festival included a giant 3D elephant projected over the River Wear. However, while it was installed and taken down, roads were closed and shoppers diverted away from the area.
The Oxfam bookshop and boutique were two shops affected. Their manager, Michael Ridsdale, said the two shops lost £2,500 in one week before the light festival had even begun.