"The highest wage prescribed is R14.87 per hour for shop managers in urban areas, down to R3.12 per hour for security guards in rural areas in the former TBVC states," he said in a statement.
Details of the minimum wages, as well as basic employment conditions for workers in the sector, will be published in the Government Gazette on Friday.
For the first time, workers from the former Transkei, Bophuthatswana, Venda and Ciskei homelands have been incorporated in the legislation.
"Concessions have been made to allow for the phasing in of the minimum wage in these regions.
"Initially, employers in these regions will pay 30% less than other areas, with annualised increases aimed at reaching the same levels... for other areas by February 1, 2006."
Prescribed minimum hourly wages for 2003 in South Africa's urban areas include: R4.03 for a cashier, R4.84 for a sales person, R3.08 for a general assistant, and R6.95 for an assistant manager.
The department said wage levels would differ for "intermediate and rural areas", as well as in the former TBVC areas.
Wages were set for a three-year period, with 8.8% a year increases for the second and third years.
Mdladlana said casual workers in the wholesale and retail sector were particularly vulnerable, and had little job security.
"In this light I want to emphasise that all workers are now entitled to a minimum wage, irrespective of the number of hours he or she works, and all are entitled to benefits such as leave or notice pay," he said.
Thursday's announcement follows the setting of minimum wages for domestic workers and in the agricultural sector earlier this year.