Parliament Speaker Herman de Croo canceled a planned lunch when he learned that the Iranians would prefer he serve no alcohol.
"I was indirectly asked not to serve alcohol," he told the newspaper De Standaard. "Even for someone tolerant like Herman De Croo, that's going a bit far."
After that, Senate President Anne-Marie Lizin refused to meet the delegation because she discovered they were unwilling to shake hands with her.
"We tried to find a solution, but they held fast to their position of not wanting to shake her hand," her spokesman Patrick Peremans told the BBC.
Officials said no one expected the Iranians to drink wine, since consumption of alcohol is forbidden by the Koran.