This special issue aims at provoking discussion on the systematic contribution that ethnographic studies in the field of Early Childhood Education and Care (ECEC) can make to enquire into the question: "What matters in early childhood education and care?" In so doing this issue examines "what" matters and "how" ECEC matters to children, parents and educators, which challenges simplistic notions about 'what works' for all children, families and educators, for all time, and in all contexts. The papers in this special issue focus on ECEC, which is a period of pre-compulsory education, and the emphasis is on education and care provided as group-care in public institutions as opposed to that provided at home. The period 'early childhood' is not uniform and varies according to the age a nation or region sees fit for young children to enter compulsory schooling.