Research Findings: This study examined the validity and reliability of the Classroom Assessment Scoring System (CLASS; R. C. Pianta, K. M. La Paro, & B. K. Hamre, 2008) in Finnish kindergartens. A pair of trained observers used the CLASS to observe 49 kindergarten teachers (47 female, 2 male) on two different days. Questionnaires measuring teachers' efficacy beliefs, exhaustion at work, and classroom interactional style (i.e., affection, behavioral control, and psychological control) were completed by the teachers. Confirmatory factor analysis indicated that when the item measuring Negative Climate was excluded, the 3-factor solution assuming three positively correlated latent factors (i.e., Emotional Support, Classroom Organization, and Instructional Support) described classroom quality well. The CLASS also showed high item and scale reliabilities. Evidence for concurrent validity was indicated by the positive association between observed classroom emotional support and teacher-rated affection and self-efficacy. Teacher-rated affection was also associated with observed classroom organization. Practice or Policy: The findings provide support for the CLASS as a valid and reliable measure of classroom quality in kindergartens and in cultural contexts outside the United States. (Contains 5 tables and 2 figures.)