Judge and Keep New Zealand Beautiful CEO Heather Saunderson said the cities displayed a strong focus on making their environment more vibrant and rubbish-free.
"They have a huge focus on the arts and beautification, and both have well established top-of-the-line recycling facilities. The only tangible difference between the two is scale, so we decided to award them both," Saunderson said.
Last year, Whanganui took out the award for the first time, beating Hutt City.
Also centrestage at the awards was Progress Castlecliff, taking out the Community Group Award for their work beautifying Whanganui's largest coastal suburb.
In the Best Street category, two of the three nominees were in Whanganui, with Victoria Ave and Rangiora St celebrated. It wasn't enough on the night however: Cambridge's Victoria St took the title.
Last year, Whanganui's Ridgway St won the award.
Journalist and awards judge Rachel Grunwell said the awards shine a light on the work of organisations in the community.
"It's been hugely enjoyable to explore our back yard while talking to community groups and organisations about the work they are doing to keep this country beautiful," Grunwell said.
"The range of initiatives shows that no matter how big or small, every effort in minimising litter in New Zealand is important and makes a difference, and I find it very inspiring."