The tourism industry was among the early adopters of information and communication technology (ICT), such as the Computer Reservation System of the early 1950s and the adoption of Global Distribution Systems in the late 1980s. However, after several decades of ICT adoption, the degree of adoption as well as use of ICT among enterprises related to travel and tourism (T&T) has been quite uneven. The objective of this study is to provide a model that explains the ICT adoption process in the T&T industry through a combination of Adoption Diffusion (AD) and Usage Diffusion (UD). The model incorporates the UD concepts of variety of use and rate of use with the perceived usefulness concept of AD. The UD model, unlike the AD model, focuses on the extent of use rather than on the act of adoption. The model consists of three main parts, namely, determinants, user patterns and outcomes. Based on these three dimensions, adopters are categorized into eight groups: Tech-Savvy, Obligatory, Early Adopter, Focused, Limited, Constrained, Follower and Laggards. The model was empirically tested and the results show that perceived usefulness is an important element in the adoption process. This model will be a ready reference for professionals, managers working in T&T firms, policy makers and government bodies in strategy formulation. It will also help IT professionals and researchers who work in the T&T domain.