The burst has hit a 22-inch water main in Orchardhead Loan in the city’s Liberton area.
The company said supplies in the city centre, Old Town, Canongate, Liberton, Prestonfield, and The Inch could be affected.
It has also caused some flooding in the Orchardhead Loan area.
Scottish Water said its engineers were working to fix the problem and restore supplies as quickly as possible.
In a statement on its website, the firm said: “Scottish Water is liaising with the Scottish Fire and Rescue Service and other agencies.
“We apologise for any disruption to customers.”