Mobile data services are increasingly important as revenues from voice calling are decreasing for mobile carriers, and there are many predictions that the use of mobile data services will increase in Australia. However, there is little research on the current use of mobile data services. This study explores the characteristics of mobile data service users. We conducted a survey with over 6,000 respondents. The findings show that as in the early stage of the Internet diffusion, age is the most important demographic variable which influences the pattern of mobile data service use. In addition to age, gender and household income have a role in describing each group’s consumption of mobile data services more precisely. We conclude the paper by presenting limitations of the study and outlining some possible future research.