The fire spread so fast inside the packed club that firefighters and ambulances could do little to stop it.
Police Major Cleberson Braida Bastianello said the toll had risen to 233 with the death of a victim in hospital.
Federal Health Minister Alexandre Padhilha told a news conference that most of the 117 people treated in hospitals had been poisoned by gases they breathed during the fire. Only a few suffered serious burns, he said.
Brazil president Dilma Rousseff arrived to visit the injured after cutting short her trip to a Latin American-European summit in Chile.
“It is a tragedy for all of us,” Ms Rousseff said.
Santa Maria mayor Cezar Schirmer declared a 30-day mourning period, and Tarso Genro, the governor of the southern state of Rio Grande do Sul, said officials were investigating the cause of the disaster.
The blaze was the deadliest in Brazil since at least 1961, when a fire that swept through a circus killed 503 people in Niteroi, Rio de Janeiro.