Three studies were conducted with the goal to articulate and test models for integrating the concept of motivation to reduce uncertainty into the axiomatic structure of uncertainty reduction theory. Multiple models were considered, each model defining motivation to reduce uncertainty in a different way. Motivation to reduce uncertainty was defined as a scope condition (Model 2), as tolerance for uncertainty (Model 3), as a weighted function of uncertainty by its importance (Model 4), and as the difference between one's uncertainty level and one's tolerance for uncertainty (Models 5a and 5b). Each of these models was compared to the baseline model (Model 1) derived from the original presentation of the theory where level of uncertainty, by itself, serves as a determinant of various communication behaviors. Tests of these models in terms of their ability to predict information seeking and attraction reveal that none of the models provides a consistent integration of motivation to reduce uncertainty into uncertainty reduction theory. Rather, tolerance for uncertainty (Model 3) is one of three determinants of information seeking, while level of uncertainty (Model 1) is one of three determinants of attraction. This inability to integrate motivation to reduce uncertainty into uncertainty reduction theory can be attributed to the consistent failure to find support for deviance and incentive value as determinants of tolerance for uncertainty, the rejection of Axiom 3 in uncertainty reduction theory (which specifies a positive relationship between uncertainty and information seeking), and the rejection of Theorem 17 (which specifies a negative relationship between information seeking and liking).