Magistrate Munato Mutevedzi ruled that former lawmaker Munyaradzi Gwisai and five others will face treason charges during a March 21 hearing. Treason is punishable by death.
The group was arrested Feb. 19 while attending a lecture and watching television footage of recent uprisings in North Africa. Police say they were preparing for an anti-government revolt. The group says it was only an academic lecture and denies wrongdoing.
Mutevedzi dismissed charges against the 39 and said police had made "dragnet" arrests. He said prosecutors failed to show that they had any intention to overthrow the government.
Prosecutors allege Gwisai and the other participants held the meeting to "organize, strategize and implement the removal of the constitutional government of Zimbabwe … the Egyptian way."
Mutevedzi described the meeting as "not idle talk.
"There was an intention to incite others to undertake an act that constitutes conspiracy and viewing of video footage was clearly shown to do that," he said.
Defense lawyer Marufu Mandevere said some members of the group were held in solitary confinement following earlier accusations that they were tortured and denied medical treatment and access to their lawyers.
Defense lawyers argued last week the case was groundless and demanded all suspects be released.
Mutevedzi, the magistrate, said there were "glaring weaknesses" in the state’s case, including lack of evidence, which had to be dealt with during the trial.
Gwisai has complained to the court he was repeatedly beaten with a wooden plank and told to confess that he called for the ouster of President Robert Mugabe during his detention.
Mugabe has been in power since independence in 1980. Critics accuse him of violently suppressing the opposition and destroying the country’s economy through a land redistribution program.
Though he entered in a power-sharing deal with Prime Minister Morgan Tsvangirai, the country’s longtime opposition leader, after the violence-plagued 2008 elections, Mugabe has said he has the power to unilaterally call elections this year to end the shaky coalition government.
Security authorities have said they will clamp down on any alleged plotters of "destabilization."