People would respond more quickly to losing a bankcard than suffering the symptoms of a stroke, a survey says.
Strokes are caused by bleeds or clots in the brain
The Stroke Association poll of 2,000 people suggests 88% would react immediately if they lost a bank card.
This compared with 34% of people it suggested would wait 24 hours if they experienced facial or arm weakness and speech problems - symptoms of a stroke.
Just 33% of those polled were aware a stroke caused immediate brain damage. Experts say the findings are worrying.
The over-65s were among the least likely to seek immediate assistance - despite 75% of strokes happening to that age group.
The survey also suggested that 69% of women would call 999 immediately on noticing symptoms, compared with 59% of men.
Joe Korner, director of communications at the Stroke Association, said: "These results highlight how strokes continue to be misunderstood by the public and is way down on their agenda.
"People simply do not realise the devastation that a stroke can cause or that it can be prevented."
An estimated 150,000 people have a stroke each year in the UK. It is the third most common cause of death.
More than 250,000 people live with disabilities, such as paralysis or inability to speak, caused by a stroke.
The symptoms include facial weakness, arm weakness and speech problems. Doctors recommend that anyone discovering any one of those signs should seek emergency medical assistance.
A Department of Health spokesman said efforts were being made to improve the public's knowledge about strokes.
"Our current consultation - A New Ambition for Stroke - is aimed at improving public awareness of stroke.
"We have also taken some steps in advance of the publication of the stroke strategy later this year including working with NHS Direct, and ensuring that the Get The Right Treatment campaign prompts people with suspected strokes to go to their emergency department."