Voting is due to take place on 14 August but the Christian children's charity says apprehension is growing about the impact of political change on the country, which has suffered economic collapse and food shortages in the last decade.
Churches are being asked to pray for peace and stability, as well as Viva's work in the country supporting children in deprived communities.
Viva Network Zimbabwe is working in four such communities in capital city Harare. The work focuses on education, safety and the family in particular, and includes Learning Support Centres where children are able to catch up on their education.
Jonathan Chikumbu, coordinator of Viva Network Zimbabwe said: "We are not ashamed to say that we need our brothers and sisters, many hundreds of miles away from Harare, to work together with us to make this nation a place of hope where children can fulfil their God-given potential."
Viva Network Zimbabwe covers 31 organisations and 35 churches reaching a total of 4,000 children. One child helped by the centres was Farai who suffered the loss of both parents and was no longer able to go to school. He was helped by a teacher at the Viva-supported Mbare Learning Support Centre in Harare and after 18 months, was able to return to mainstream school.
Although the economy has started to recover and the coalition government has brought greater political stability, Viva says the gap between rich and poor is widening and that this may cast a shadow on the futures of children from poor families.
Viva's Patron, the Reverend Stephen Gaukroger, is supporting the call for prayer.
He said: "We are calling on churches to make Zimbabwe a focus for prayer at this crucial time. It's a call to pray against violence and fear, and a call to pray for peace and stability.
"We are also calling on churches to give towards Viva's projects in Zimbabwe so children there can grow up knowing they have a future and a hope."