OBJECTIVE To describe morbidity associated to varicella in children attending day care centers. METHODS Descriptive study carried out through inquiries with parents of 664 children who acquired varicella after admission to day care centers in Taubaté (population: 244,165, census of 2004), a prosperous city in the State of São Paulo. RESULTS The median age was 36 months (range 6 to 80 months); 8.4% of the children had varicella before 1 year of age. The main symptoms were: exanthema (100.0%), fever (85.4%) anorexia (39.6%), and headache (15.3%). 517 children (77.9%) had at least 1 medical visit, and 80.6% received at least 1 medication; 73 (11.0%) received nonsteroidal antiinflammatory drugs, and 52 (7.8%) received antibiotics. Complications occurred in 38 children (5.7%; 95% confidence interval: 3% - 8%); 8 (1.2%) were hospitalized, and 5 (0.7%) had sequelae. Complications and hospitalizations rates were 3 times more frequent in children with less than 1 year of age than in older children. More than half of the children and of the working parents were absent from their regular activities for more than a week. CONCLUSIONS Varicella was associated with significant morbidity, affected younger children, was complicated in more than 5%, and left sequelae in 0.7% of children. More than 10% of the children received nonsteroidal antiinflammatory drugs, highlighting the need to warn the population about the risks of these drugs. Although varicella vaccination is not recommended for children younger than 12 months, vaccination of the children older than a year could avoid by herd immunity the transmission to babies. Brazilian public health authorities should be alerted to this issue and offer varicella vaccine to children attending day care centers.