Sustainable Development Goal Target 4.2.1 is monitored by determining the proportion of children aged 24 to 59 months who are developmentally on track in the domains of health, learning, and psychosocial well-being. UNICEF has developed a caregiver report measure, the Early Childhood Development Index 2030 (ECDI2030), to measure progress towards this target. This paper examines whether a newly developed tool, the Early Childhood Development Assessment Scale--Direct Assessment (ECDAS-DA) can add value to the measurement of Target Indicator 4.2.1 by complementing UNICEF's ECDI2030, and explores the psychometric properties of the ECDAS-DA. A total of 956 children (476 girls) aged 3 to 5 years from Bangladesh, China, India and Myanmar were administered the ECDAS-DA in individual sessions. Caregivers provided responses to a survey based on UNICEF's ECDI2030. Confirmatory Factor Analyses indicated that learning, health, and psychosocial well-being domains of the ECDAS-DA were three component parts of one underlying construct of early child development. Significant correlations between the ECDAS-DA and the caregiver-reported ECDI2030 survey were found in the learning and health domains but findings were mixed for the psychosocial well-being domain. Multiple measures of early development could be important in measuring SDG Target 4.2.1 and the ECDAS-DA has the potential to complement UNICEF's ECDI2030.