The aim of this study was to explore oral health-related knowledge, attitudes, and beliefs among 11 to 12-year-old schoolchildren with favorable, moderate, or poor behavior related to oral health. The data were gathered by questionnaire. Recommendations commonly used in Finland in oral health education were chosen as the criteria for selection of groups of children with favorable, moderate, and poor oral health behavior. Differences between groups were analyzed using crosstabulations and factors related to unfavorable behavior using logistic regression analysis. The percentage of children with appropriate knowledge was higher in the good behavior group (GB) than in the other groups. The groups differed most in the children's knowledge of the recommendation to use fluoride toothpaste at least twice a day. Most children in the GB group considered it important to brush their teeth for the fresh feeling this gave. The majority of children in all groups considered it important to brush their teeth when going to the dentist. The majority also considered brushing important for avoiding tooth decay and tooth discoloration as well as for having fresh breath. Unfavorable knowledge, attitudes, beliefs, and behavior tended to accumulate in the same children. Factors associated with unfavorable behavior were male sex, mother's low skill occupation level, and child's poor knowledge of oral health-related facts.