Ethiopia has scaled up integrated community case management of childhood illness (iCCM) in most regions. We assessed the strength of iCCM implementation and the quality of care provided by health extension workers (HEWs). Data collectors observed HEWs' consultations with sick children and carried out gold standard re-examinations. Nearly all HEWs received training and supervision, and essential commodities were available. HEWs provided correct case management for 64% of children. The proportions of children correctly managed for pneumonia, diarrhea, and malnutrition were 72%, 79%, and 59%, respectively. Only 34% of children with severe illness were correctly managed. Health posts saw an average of 16 sick children in the previous 1 month. These results show that iCCM can be scaled up at scale and that community-based HEWs can correctly manage multiple illnesses. However, to increase the chances of impact on child mortality, management of severe illness and use of iCCM services must be improved.