This research investigates how consulting early childhood special education teachers (ECSETs) perceived teamwork in early childhood education and care (ECEC) centers. The following research questions were set: (1) What constructs or prevents the functionality of teamwork in ECEC according to ECSETs experiences, and (2) what are the perceived consequences of teamwork in ECEC as experienced by the ECSETs? We arranged 13 group discussions in which 35 ECSETs discussed their own experiences of successful teamwork in ECEC. Using a phenomenographic approach, we identified four factors that impacted the functionality of the teams: external, unit-specific, team-specific, and employee-specific factors. ECSETs described how teamwork specifically affects the quality of ECEC and the implementation of educational support for children. Our research will help in understanding the factors and functions of teamwork as well as to develop team strengths and practises in ECEC centers.