Washington was one of 16 pro entrants in the Men's Physique category; and was pleased with his placing.
'Work on improving'
"We got top five," he said on social media. "I am very happy with the look I brought for the last competition of the year and thank you all for the support; it's time to work on improving."
Washington has been vegan since 1998, a decision he made linked to his Rastafarian beliefs and an urge to avoid harming animals.
Washington was not the only vegan at the event. Jehina Malik competed for the first time since her involvement in a road accident that came close to killing her.
After a long rehabilitation she has started training again and made it to the stage in the Women's Physique category.
Making the stage after the accident is a major achievement, although Malik told Great Vegan Athletes: "I'm not finished yet."
The athlete has been vegan since birth and enthusiastically continues this lifestyle in competition.