While much has been published about the ways in which students gain from contact with faculty, much less is known about the patterns and correlates of such contact for faculty members. Drawing upon data from a survey of faculty (n=901) conducted at a large, highly selective, research-extensive university in spring 2004, this study explores the factors that promote or inhibit faculty members’ engagement in two types of out-of-class interactions with undergraduate students: research-based activities and other out-of-class activities that are less narrowly focused on academic issues. We test four explanations of faculty engagement using OLS regression, and estimate separate models for research-based and other types of out-of-class involvement. Our results provide little support for two of the most prevalent explanations of factors that inhibit faculty involvement: competing time demands, and a lack of institutional rewards or supports for out-of-class interaction. Two other explanations received more support. First, faculty members’ personal values and beliefs were strongly associated with their extent of engagement in out-of-class interactions, particularly for non-research based interactions. Second, the block of variables reflecting faculty members’ interpersonal knowledge and abilities had the strongest association with engagement in out-of-class interactions; this relationship was nearly twice as strong for activities that were not research-based than for those that were circumscribed as research. Our findings suggest that institutions may best be able to support out-of-class interactions between faculty and undergraduate students by brokering information flows concerning opportunities for engagement and the actual “how to’s” of making such interactions work.