Alun Elder-Brown, a recruitment executive, said he was left feeling "like a piece of dirt" after being barred from bringing the animal into Kirthon Restaurant in Tunbridge Wells, Kent, on religious grounds.
The Guide Dogs for the Blind Association said the decision was illegal under the Disability Discrimination Act and Mr Elder-Brown, 51, is now considering suing the establishment in The Pantiles.
It follows a series of successful prosecutions of Muslim taxi drivers who refused to carry guide dogs in their cars because they considered them unclean on religious grounds.
Mr Elder-Brown was taking his girlfriend out to celebrate her birthday with her five year-old daughter last week when he was told he would have to leave his dog, Finn, tied up outside.
He showed a card issued by the Institute of Environmental Health Officers certifying he and his dog were allowed into any premises but an argument ensued and the owners threatened to call the police if he did not leave.
"I was made to feel like a piece of dirt. They told me I couldn't come in because it was against their religious beliefs to have a dog in the restaurant.
"They then said I could leave Finn tied up outside. I stayed calm but when they threatened to call police I left."
He added: "It was horrible. It put a dampener on the whole celebration."
Under the Disability Discrimination Act it is illegal to refuse to serve a disabled person of give them a diminished level of service because of their disability.
Chris Dyson of Guide Dogs for the Blind said: "We are extremely concerned and disappointed that Alun was refused access to this restaurant.
"We very much hope that this restaurant will reconsider its decision and get in touch with the charity so that we can give them a better understanding of their requirements under the law and explain the important role that the guide dog plays for Alun."
The restaurant's owner, Amenur Abdussamad, was not immediately available for comment.
But Shamin Ahmed, a partner in the restaurant, said that he had written to Guide Dogs for the Blind to apologise for the incident.
He said that although the owners of the venue are Muslim, he insisted religion was not a factor in the decision to refuse Mr Elder-Brown.
“We were worried about the hygiene, that is what happened, it was a mistake,” he said.
“I have had a letter from Guide Dogs for the Blind, I have sent a reply apologising about that.... we found out afterwards that guide dogs are allowed, I didn’t know that.”