The purpose of this study was to investigate the relationships between Internet usage, social isolation, and Internet addiction among university students. The study used a quantitative method and questionnaires to measure the ‘problems of using the Internet’, ‘patterns of Internet usage’, ‘social isolation’, and ‘Internet addiction’. The study included 440 students from the University Putra Malaysia, chosen using a stratified random sampling method. The majority of the respondents were single (93.20%) and aged between 23 to 40 years old. The study found a significant relationship between ‘problems of using the Internet, social isolation, and Internet addiction’. However, there was no statistically significant relationship between the patterns of using the Internet and social isolation. The t-test result showed that no significant mean differences were found among marital status, field of study, social isolation, and Internet addiction. Implication of the study discussed.