This review discusses basic features of Implicit Association Tests (IATs) that are relevant in order to estimate their suitability of IATs for the valid assessment of individual differences. We start with a description of the essential characteristics of the procedures of IATs and also refer to theoretical accounts for IAT effects. Then, we provide an overview of research on the psychometric properties of IATs including their reliability and incremental validity for the prediction of behavior over and above explicit measures. Finally, we describe some alternatives to IAT measures and offer an outlook for future research.