This study examined the psychometric properties of a social-networking site (SNS) activities scale (SNSAS) using Rasch Analysis. Items were also examined with Rasch Principal Components Analysis (PCA) and Differential Item Functioning (DIF) across groups of university students (i.e., males and females from the United States [US] and Europe; N = 840). Results from this study found psychometric support for the SNSAS to measure endorsement of activities in which university students engage. European males and females were more likely to endorse actively using SNSs compared to their more passive US counterparts. The SNSAS is a reliable and valid tool in a growing research area where few exist. University administrators worldwide can benefit from understanding the patterns of SNS behavior that may impact students' socialization, relationship formation, and academic outcomes.