This study examined the value of using a group-centered approach to evaluate process quality of early childhood education and care (ECEC). Is observed support of group processes a different aspect of classroom quality, and does it predict children's collaborative play in ECEC in the Netherlands? In two play situations, 37 teachers and 120 two- to four-year-old children were observed with the Classroom Assessment Scoring System (CLASS) Toddler and two new measures. In a two-level structural equation model, teachers' support of group processes was positively related to the CLASS domains and to children's collaborative play, over and above the effect of children's cognitive ability and social competence. These findings suggest that ECEC quality evaluation could be enriched by adding group-centered indicators of classroom quality.