There is a growing body of evidence that feeling present in virtual environments contributes to effective learning. Presence is a psychological state of the user; hence, it is generally agreed that individual differences in user characteristics can lead to different experiences of presence. Despite the fact that user characteristics can play a significant role in research on presence, most studies on the determinants of presence focus on immersive, interactive, and perceptually realistic aspects within the technology. Research into user characteristics and how they affect presence has received little attention thus far. The purpose of this study is to explore how user variables combine and interact to predict the level of presence in a 3D virtual learning environment. One hundred and eighty-five nursing students participated in this study and completed a questionnaire measuring user variables. Structural equation modelling was employed as the main technique for data analysis to ensure methodological rigor. The findings indicate that subjective norm, perceived ease of use, computer self-efficacy, and perceived usefulness account for 52% of the total variance of the sense of presence. This study makes a significant contribution by developing and validating an initial model of the determinants of presence in a 3D virtual world.