Police said demonstrators blocked the road leading into Jerusalem and threw stones at officers in scuffles when around 500 people protested at the entrance to the holy city before moving on to outside parliament.
"Nineteen people were arrested for disorderly conduct. Five police officers were lightly wounded, including one mounted policeman, who had his arm broken by stones that hit him," said police spokesman Micky Rosenfeld.
"It was a demonstration for rights of equality. They feel they are treated differently," he added.
The protestors accused the state of discarding blood donations given by members of Israel's 60,000-strong Ethiopian Jewish community, and a lack of equality in academic institutions and the job market, an AFP photographer said.
The health ministry said it applied the same standards to anyone wishing to donate blood.
"When you fill out the required form to donate blood, there is a very clear and elaborate part that lists the situations under which your blood will not be used," Boaz Lev, the ministry's associate director general, told AFP.
Included in such cases are haemophilia, and long stays in countries with epidemics that could affect blood supply or in countries with a high incidence of HIVAIDS, among others, Lev said.
"We didn't invent anything, these are international standards," he said.
Ethiopian Israelis last held violent protests in 1996 after discovering the government blood collection agency systematically destroyed their donations due to a relatively high incidence of HIV infection.
Ethiopian Jews were brought to Israel in two major airlifts in 1984 and 1991 but they have since had difficulty being absorbed into Israeli society, where they complain of economic and social discrimination.

Copyright AFP (Agence France-Presse), 2006