This study aimed to assess the efficacy of the developmental assessment of young children second edition (DAYC-2) Scale in detecting Developmental Delay among Jordanian children aged birth to 71 months. Firstly, the scale was translated and reviewed for language and cultural appropriateness. Secondly, the Arabic Jordanian version of the scale was administrated to children diagnosed as developmental delay aged from birth to 48 months in the neurodevelopmental pediatric clinic in Jordan university hospital, and on children aged 48 to 71 months who were diagnosed as developmental delay in special education centers in Capital Amman. The scale was administrated also to normal development children aged 0 to 71 months who visited the Institute for family health--Noor al Hussein foundation and attended preschools in Capital Amman. Total of 310 children aged (0-71 months) were enrolled. Construct validity and discriminative validity were verified. Reliability was established through computing Kuder-Richardson Formula 20 (KR-20), test-retest, split half test methods.t-test showed that the scale discriminates between normally developed and developmentally delayed children. One-way ANOVA showed that age has significant effect on the performance of children favoring older age groups using Scheffé multiple comparisons test. Item efficacy was determined by calculating point-biserial correlation coefficients for all items in each domain. The results showed that the scale had good psychometric properties and was capable of detecting developmental delay in children aged from birth to 71 months in Jordan.