The use of suspension practices is extremely widespread but few studies have examined the behavioral and psychological outcomes associated with their application. Using a predominantly Black sample of 788 middle school students from the Midwestern United States, the current study evaluates the relations between in-school suspensions (ISS) and out-of-school suspensions (OSS) received during the course of the school year and student self-efficacy, engagement, prosocial behavior, emotion regulation, concentration, internalizing problems, and disruptive behavior based on student and teacher ratings collected at the end of the school year. Regression models were used to evaluate associations between the total number of ISS and OSS exposures on end of school year outcome measures controlling for beginning of school year measures and demographic characteristics. Results indicated that ISS and OSS are both associated with less prosocial behavior, lower levels of emotion regulation, and a greater extent of disruptive behavior and concentration problems at the end of the school year, even after controlling for these behaviors at the start of the school year. Implications of the potential impacts and distribution of suspension practices are discussed. [For the corresponding grantee submission, see ED625979.]