Teaching Strategies GOLD® child assessment system has been frequently adopted in state-funded early childhood policy initiatives, but there is little validation research about its newest edition, GOLD® Birth through Third Grade (GOLD® B-3rd). Based on a sample of children aged from birth through pre-kindergarten, this study investigated validity evidence regarding internal structure of this observational assessment, and the reliability estimates for each learning domain. From the results of confirmatory factor analysis, acceptable fit of the proposed measurement structure and high composite reliability estimates for the learning domains were found. We found evidence that the GOLD® B-3rd is a psychometrically adequate measure (to the extent of its internal structure) of developmental progress in social-emotional, physical, language, cognitive, literacy, and mathematics domains for young children. Findings of this research add to the body of validation research of GOLD® B-3rd, and encourage future investigations on other types of validity evidence for this scale. (author abstract)