Social skills are an important part of development, and deficits in this area have long-term impacts on a child. As a result, clinicians should include a measure of social skills as part of a comprehensive assessment. There are a few well-researched measures of social skills that are currently used, including the Matson Evaluation of Social Skills with Youngsters (MESSY). The MESSY has been translated and studied internationally in more than nine countries; however, updated norms for the United States have not been conducted since the inception of the measure. The purpose of this article is to examine the psychometric properties of the MESSY using an updated norm sample and age cohorts. Overall results indicated strong internal consistency and good to strong convergent and divergent validity. Psychometric properties for the older age cohorts were stronger and more consistent than those for the 2- to 5-year-olds. This reflects the variability of development and difficulty of assessing social skills at this young age. (Contains 5 tables.)