The condition affects more than 600,000 people in the UK, making it one of the most common neurological conditions.
Scottish charity Quarriers commissioned a study of experiences of epilepsy, which surveyed 505 people across the UK.
One woman in Glasgow said she was mugged while having a seizure.
More than two-thirds of the 505 people interviewed in the ComRes poll admitted to worrying what members of the public would say or do if they had a seizure.
A third admitted this concern led to anxiety about whether to leave the house, while just over half believed discrimination was widespread.
About the same amount of respondents felt others treated them differently after they revealed they had the condition.
Sara Brannan, who lives in Glasgow with her 10-year-old daughter Mary-Jo and husband Paul, said she had money taken from her while she was having a seizure.
She said: "A man, who I now think may have been a drug addict, must have been standing behind me and spotted an opportunity.
"He told the gathering crowd I was his girlfriend and had overdosed. He took my money and my shopping bags.
"I've been told people have stepped over me while I've been lying unconscious.
"I was once kicked out of a shop just before I was about to take a seizure after asking for a glass of water so I could take a tablet to try to prevent it coming on.  I guess the shopkeeper thought I was an addict of some kind."
Gerard Gahagan, head of clinical services at Quarriers, said: "Around one in 100 people in the UK suffer from epilepsy, so there is a high probability perpetrators of the discrimination could actually have a relative or friend who is avoiding revealing they live with the condition because they fear what the reaction will be."
Quarriers will open a new Â£6.4m epilepsy centre in Govan in Glasgow next year.
The number of people with epilepsy in Scotland has increased by almost 40% in just six years, according to figures which came out at the end of last year.
People with epilepsy are facing discrimination and many worry about leaving their homes in case they have an attack, a survey has suggested.