State and trait anxiety theory and assessment are reviewed. The person (trait anxiety) and the situation are important in determining levels of state anxiety. The facet of trait anxiety and the stressful situation must be congruent in order to evoke increases in state anxiety. The multidimensional interaction model is reviewed and empirical research is presented. A discussion of anxiety viewed in a dimensional versus a categorical conceptualization is presented. Misconceptions regarding the multidimensionality of trait anxiety are discussed. Finally, it is concluded that anxiety should be viewed as a dimensional construct and that the multidimensionality of state and trait anxiety should be considered in both theory and assessment.