Association between oral health status and nutritional status was investigated in 200 semi-institutionalized persons with mental retardation aged 5-53 years, 45.5% female, in the cities of Florianopolis and Sao Jose, province of Santa Catarina, Brazil. In this cross-sectional study, clinical-odontological examination revealed a high percentage of individuals (68%) with heavily compromised dentition. The index of decayed, missing and filled deciduous and permanent teeth, which increased from 2.85 plus or minus 2.87 in children to 20.5 plus or minus 6.86 units in adults, was used to classify the individuals' oral health status. Anthropometric evaluation revealed the prevalence of suboptimal nutritional status in 52% of children and adolescents [22% underweight, 30% at risk of overweight or overweight], and in 60% of adults [7% underweight, 53% overweight or obese]. Significant association was found between unsatisfactory oral health status and overweight in children (chi[superscript 2] = 4.627; p = 0.031). Findings evidenced the existence of a relationship between oral health status and nutritional status in persons with mental retardation. (Contains 3 tables.)