Zimbabweans can get permits to stay legally in South Africa for six months, the authorities have announced.
Some three million Zimbabweans are believed to have crossed the border to escape the economic collapse and human rights abuses at home.
The permit gives migrants the right to work and get healthcare and education.
An official said the permits would reduce the numbers claiming political asylum, which means they are not allowed to return home.
“Most Zimbabweans are not asylum-seekers, they are economic migrants. So what they want to do is to come into the country do some work and go back home and take money back,” said Home Affairs Director General of Immigration Services Jackie MacKay.
“We also believe this special dispensation will result in foreign currency going into Zimbabwe and assist in building up that country,” he said.
The economic situation in Zimbabwe seems to be showing signs of improving, since long-time opposition leader Morgan Tsvangirai joined a power-sharing government in February.
Mr Mackay said the situation would be reviewed after six months.
The BBC’s Mpho Lakaje in Johannesburg says the announcement will come as a great relief to many Zimbabweans, however some believe it is too good to be true.
Zimbabweans must apply for the permit through the department of home affairs and it will be processed with the UN refugee agency, Mr Mackay said.
South African police frequently deport Zimbabweans found without the correct paperwork.
But many just return through holes in the fence along their common border.
Last year, there were widespread attacks on foreigners living in South Africa, which left at least 62 people dead and forced 100,000 from their homes.
This was partly sparked by a feeling that they were taking jobs from South Africans and getting preferential treatment for government services such as housing and sanitation.