"This country has gone through a lot of traumatic experiences," Tsvangirai said at the launch of a video on the 1980s atrocities.
"What we have to accept is that in order to heal there must be justice, and in order to have justice there must be truth," Tsvangirai said.
"That is the only way which can help us move forward as a nation. Unless the truth is told, there cannot be healing and reconciliation," he said.
"There are those who are calling for a truth commission. They are right, but without justice we cannot move forward," he added.
The video documents the Zimbabwean army’s bloody campaign known as Gukurahundi – "the rain that washes away the chaff" – when a North Korean-trained brigade is believed to have killed some 20 000 people in a counter-insurgency drive.
Tsvangirai linked the massacres of the 1980s to an operation three years ago when President Robert Mugabe’s government bulldozed the homes of 700 000 people in what was officially called a slum renewal project.
"The common thing is we have a leader and a government whose main pre-occupation is power-retention," he added.
"We created that government and the leader, and the question is how to deal with such experiences because that is human terror of unprecedented proportions."
Tsvangirai and Mugabe, who has ruled since independence in 1980, have been negotiating for weeks over a power-sharing deal following deadly electoral violence earlier this year.
The talks are stalled over control of the home affairs ministry, which oversees the police. – AFP