Purpose: To identify the risk indicators of gingivitis among socioeconomic, clinical and gender variables in 5-year-old children attending preschools in Piracicaba, Brazil, in 2005. Materials and Methods: The sample consisted of 728 subjects attending 22 public (n = 428) and 18 private (n = 300) preschools. A previously calibrated examiner performed the clinical examination in an outdoor setting, under natural light, using a dental mirror, Community Periodontal Index probe and air-drying. Gingival status was measured using the gingival alteration index for 5-year-olds according to the national survey carried out in 2002 in Brazil (Health Ministry of Brazil, 2004). Socioeconomic variables (monthly family income, number of people living in the household, parents' educational level, home ownership and car ownership) were collected by means of a parental semi-structured questionnaire. Results: The prevalence of gingivitis was 16.6%. Monthly family income (p 0.0001), father's education (p 0.0007), mother's education (p = 0.0004), type of school (p 0.0001), car ownership (p = 0.0854), gender (p = 0.0087), initial lesion (p 0.0001), dental caries (p = 0.0008), crowding (p = 0.0054) and spacing (p = 0.0019) were associated with gingival bleeding at p 0.15 and were selected for the regression analysis. By means of multiple logistic regression analyses, monthly family income of up to 4 Brazilian minimum wages, presence of initial lesion, presence of crowding and male gender were found to be risk indicators of gingivitis. Conclusion: The prevalence of gingivitis in 5-year-old preschool children in Piracicaba was 16.6%. Also, family income of up to 4 minimum wages, male gender, the presence of initial caries lesion and crowding were risk indicators of gingivitis. Keywords: gingivitis, preschool, risk indicator