Since the rainy season started in October around 20 have died in Minas Gerais state and 27 in Rio de Janeiro state.
Sergio Cabral Filho, Rio de Janeiro's new governor, went on Sunday with Pedro Britto, minister of national integration, to Novo Friburgo, one of the worst affected mountainous towns, to meet mayors of the disaster-hit region.
The federal government has allocated 57 million reais ($26.5m) for disaster relief.
Brazil's National Space Research and Climate Studies Centre said that in the first five days of January the Mantiqueira mountains near Rio de Janeiro received half the usual average monthly rainfall.
Mudslides killed 16 Brazilians in Petropolis, an historic mountain resort near Rio, in January 2003. In December 2001, 52 people died in mudslides in Rio de Janeiro state.