Many studies have been conducted to identify the factors explaining individual differences in children's emotion understanding (capacity to comprehend the nature, causes and consequences of emotions in the self and others). These studies represent a significant advance in our comprehension of the origins of the child's capacity to understand emotions. However, almost nothing is known about the impact of classroom quality on children's emotion understanding even though Western children spend about six to eight hours per day in school. In this study, we used the Early Childhood Environmental Rating Scale -- Revised edition [ECERS-R] to evaluate global childcare classroom quality in 31 classrooms located in Moscow (middle SES areas) and the Test of Emotion Comprehension [TEC] to assess their emotion understanding (N = 592) while controlling for the effects of age, gender and non-verbal fluid intelligence. We hypothesized that children from high-quality classrooms would outperform their peers from low-quality classrooms in terms of their understanding of emotions. The results showed, albeit controlling for gender, age, non-verbal fluid intelligence, that children from low-quality classrooms had a significantly higher level of emotion understanding than children from high-quality classrooms. Results are discussed both in terms of their theoretical and practical implications.