The students marched in separate columns for men and women on Tuesday, chanting slogans such as "Reform is the right of millions, a right for all Egyptians."
"We don't want security forces on campus, we don't want the regime to intervene and rig student elections on 11 November," said one of the organisers, Abdulmonem Ibrahim.
Police estimated the number of protesters at 6000, while a similar number of riot police cordoned off the university to make sure the demonstrators did not leave the campus.
The demonstration came weeks before Egyptians elect a new parliament.
Some of the banners declared allegiance to the banned-but-tolerated Muslim Brotherhood group, which plans to campaign on behalf of nominally independent candidates in the election.
A police officer said late on Tuesday that seven of the organisers who are affiliated with the Brotherhood were arrested for holding an illegal demonstration.
"We don't want security forces on campus, we don't want the regime to intervene and rig student elections on 11 November"
Abdulmonem Ibrahim, Rally organiser
This was not confirmed by the organisers, who could not be reached.
Earlier, the organisers accused the police of detaining about 100 students from southern Egypt as they were travelling to Cairo for the rally.
The demonstrators handed out flyers that demanded comprehensive political reform in Egypt, free student union elections, lower prices for textbooks and an end to state interference in academic life.
The state has been accused of interfering in the appointment of professors and hindering Islamist candidates in student elections.
The Brotherhood has been banned since 1954, but the government allows it to function within limits.
It wields considerable influence in elections, where it endorses nominal independents as it is not allowed to field candidates under its own name.