But the turn-out was lower than before, a sign, say observers, of waning enthusiasm for the fervour that drove the militants to storm the embassy.
Another sign is the piano in Hassan Eshkevari's living- room. He is a mullah, and the mullahs who govern Iran have always considered music a polluting influence of the unIslamic West. But the piano in Mr Eshkevari's home at the other end of town is proof that they are shouting in vain.
Mr Eshkevari does not play it himself - that would be asking too much of a mullah. But his daughter plays it, and Mr Eshkevari tolerates it. If the reforms, led by President Mohammad Khatami, which are shaking Iran to its foundations, are about one thing, they are about tolerance.
Take Mr Eshkevari's views on the hejab, the covering that women must wear in public. "It doesn't bother me at all," the mullah said. "Some women want to wear the hejab and some don't. Maybe personally I don't like to see women without hejab, but it doesn't bother me." Sitting in his armchair, with his mullah's robes hastily thrown on, his turban slightly awry, Mr Eshkevari resembles nothing so much as a country vicar as he fusses over the tea. A clergyman is in essence what he is - it is only Iran's Islamic revolution that has turned the mullahs into political figures.
Now, with the public mood in favour of reform, people are saying the place for the mullah is in the mosque, not the government. Mr Eshkevari agrees: "The clergy will remain religious leaders, but because of the failure of the Islamic Republic, sovereignty will revert to the people."
So, are the angry young men outside the American embassy out of touch, is Iran heading down the Western path to become a democratic, secular state? "Democracy is the most important achievement of Mankind: it doesn't belong to the West or the East," snorted the mullah.
He is one voice among millions, and an ultra-liberal at that. Few even of Mr Khatami's reformers would agree with him about the hejab, or call Islamic rule a failure.
For many in Iran, America is not the Great Satan any more. Reformers held an alternative demonstration outside the university on Wednesday, chanting the rather less fiery slogan "We will deal with the United States with rationality".
But not everybody is clamouring for the American way of life, either. This is the nation that defied the most powerful country in the world for 20 years, and even the reformers are proud of that. "We like the Western countries, but we like their technology, their freedoms," Ali Hosseini, a carpet-seller, said. "But we are Muslims and we want an Islamic way of life."
Neda Tehrani, all but her face shrouded in a chador, agreed: "I want to wear the hejab: it's my religion. And I think women should be made to wear it - these are our values."
But a few miles north, in the smart parks of middle-class Tehran, you find a different perspective. Naheed Abbasi was sitting disconsolately on a bench, in the same black chador. "I want to wear what I like, to meet men, to drink alcohol. I want to live in a Western society. But these things will never come in my lifetime."
Although the conservative mullahs are closing newspapers and jailing the outspoken, people are speaking their minds. "How can we worry about the hejab when we don't even know who we are yet?" Saeed Mohammedi, a small businessman, asked. "First, we have to learn to be individuals."
That process is under way. A people who have had every tiny detail of their lives dictated to them for two decades are demanding the right to think for themselves. On the streets of Tehran there is no one clear vision of the future, but there is debate. "What we need now is not the freedom to drink or not to wear the hejab," said Mr Eshkevari, wrapping his robes around him. "What we need is freedom of thought. We are at the beginning of the way."