Interest in Bayesian analysis of item response theory (IRT) models has grown tremendously due to the appeal of the paradigm among psychometricians, advantages of these methods when analyzing complex models, and availability of general-purpose software. Possible models include models which reflect multidimensionality due to designed test structure, construct-irrelevant variance, and mixed item formats. Using Markov Chain Monte Carlo methods, models can be estimated and evaluated for model-fit. In addition to discussing Bayesian analysis, analyses of three IRT models designed to account for extreme response style are illustrated: IRTree, multidimensional nominal response model (MNRM), and modified generalized partial credit model (MPCM). While results indicated there may be little impact of model choice on substantive trait estimates for the data set studied herein, model-fit results favored the MNRM and MPCM over the IRTree Model.