The Battelle Developmental Inventory, 2^nd Edition is a recent addition to the norm-referenced standardized developmental assessment measures of young children (BDI-II; Newborg, 2004). The current study investigated the concurrent validity of the BDI-II by comparing its Total and Cognitive Developmental Quotient (DQ) scores to WPPSI-III composite scores in a sample of young children with documented impairments. It also examined the long term stability of the Total DQ and Cognitive DQ scores across administrations. Participants (n=82) were children born between October 1, 2002 and October 1, 2005 who attended a preschool program in an urban public school district in the Northeastern United States in the year that they exited the program i.e. the year they turned five years of age. Pearson product-moment correlation coefficients and t-tests for paired samples were calculated as well as effect sizes. Results indicated that correlations between Total DQ and Cognitive DQ vs. WPPSI-III composites were moderate and strong respectively. There were significant differences in group performance in all comparisons except for those with the WPPSI-III Verbal IQ. The majority of individual participants in the Total DQ comparisons and a notable percentage in the Cognitive DQ comparisons had significant discrepant scores across the test interval. Discrepant scores were less usual in the Cognitive DQ comparison. There was a significant difference between participants' assigned category designations from the Total DQ and from the Cognitive DQ vs. the WPPSI-III FSIQ. In the stability investigation results indicated a strong correlation for the Total DQ scores across administrations with non-significant change in group performance. Half of participants' scores across the retest interval were significantly discrepant which was not atypical in the population. Weak correlation was found for the Cognitive DQ scores across administration with a non-significant change in group performance. Half of individual participants' scores in this comparison were significantly discrepant across the retest interval which was not atypical in the population. Qualitative analysis revealed that the relationships between outliers and length of time receiving special education services were random and inconsistent. Limitations were discussed and implications for research and practice were suggested.