According to Reuters news agency the churchmen have all been charged with public order offences under a tough security law introduced by President Robert Mugabe shortly before his victory in a controversial poll last March.
The group had attempted to march to police headquarters, bearing wooden crosses, to present a petition complaining about police harassment.
Zimbabwe's Government has been accused of harshly cracking down on any signs of civil unrest during the Cricket World Cup it is co-hosting with South Africa and Kenya.
Draconian measures
The lawyer for the clergymen said they had been released, but he expected that they would be summoned to court at a later date.
The clergymen, calling themselves the Zimbabwe National Pastors' Conference (ZNPC) had been dressed in dog collars and carrying three wooden crosses.
They wanted to hand over a petition to police chief Augustine Chihuri asking him "to ensure that the police force in the country performs its duties with respect for the church and every citizen of Zimbabwe".
The action followed the arrest of one of their colleagues two weeks ago at a church.
They were quoted as saying that it was their duty to overcome "unjust laws that encourage the selective and vindictive exercise of authority".
But before they could hand over their petition the 19 men were herded into two police vans and driven away to Harare's central police station.
Jonah Gokova, an official of the independent charity, Ecumenical Support Services said the group were accused of holding an illegal protest under the Public Order and Security Act.
The legislation, which critics say is designed to suppress all government opposition, forbids public meetings without police clearance.
Mr Gokova said all of the men were released after eight hours.
Relations between the Zimbabwean Government and some churches have deteriorated in recent weeks as leading clergymen have become more outspoken about political repression and economic hardship.
Turbulent priest
The detentions followed an incident earlier on Friday in which the outspoken Catholic Archbishop of Bulawayo, Pius Ncube, was cautioned by police over a service he held during which victims of torture gave testimonies.
The archbishop said two plain clothes officers visited him and warned him that his services were expected to be of purely religious nature.
He said he told the police that it was impossible to separate issues of hunger, economic hardships and violence from religion.
"If people are suffering... the church cannot excuse itself," he told AFP.
"I am not going to protect a government that has abused people's rights flagrantly and for no reason. People have been killed and those who killed are running scot free on the streets because they acted on behalf of the government," Archbishop Ncube said.
Earlier this week, a small group of Zimbabwean church leaders, led by Archbishop Ncube, marched into the Bulawayo cricket ground just ahead of a Cricket World Cup match with Australia.