Despite the sexual revolution, women are still more knowledgeable than men. Awareness was highest among 18- to 29-year-old women - for whom taking care of clothes is clearly important.
Chris Lever, from Morphy Richards, said: "Clothes Care symbols are a unique language, clearly a language that few people in the UK have taken the time to learn.
"Learning the basics such as which icon represents tumble dry and which represents normal wash would go a long way to getting the best out of clothes."
The Home Laundering Consultative Council, which promotes symbols, said it was not surprised to learn that people were unfamiliar with them.
"It's disappointing that there is a lack of recognition, but it's a story that's repeated time and time again," said a spokesman, Adam Mansell. "We are a small organisation and we don't have a big budget."