Purpose -This study aims to investigate the extent and level of internet access and use among scientists at Olabisi Onabanjo University (OOU), Ago Iwoye, Nigeria, its impact on their academic activities and the constraints faced in internet use. Design/methodology/approach -A questionnaire survey with all the 125 scientists in the Faculty of Science of OOU was conducted between March and April, 2009. This was supplemented with interview and personal observations. Demographic data, pattern of internet use, impact of internet on academic activities and problems faced when using internet were assessed. Data analysis was by simple descriptive statistics. Findings -The use of internet use was widespread (100 per cent) among the scientists with the majority (43.6 per cent) using it every day, and mean internet use experience being 6.3 years. The majority of respondents (64.5 per cent) accessed the internet from a commercial cybercafé followed by homes (49.1 per cent). Most of the respondents (59.2 per cent) acquired internet use skills through colleagues and friends and 32.7 per cent on their own by trial and error. The respondents used internet mostly for communication, research and updating knowledge. Email was the most popular internet service, while Google, followed by Yahoo and Scholar Google, were the most used search engines. The majority of the scientists (67.3 per cent) prefer getting information from the internet, while less than one-third (30 per cent) still prefer the traditional library. More than half of the respondents (53.6 per cent) were not using library free full text online resources such as AGORA and HINARI, and most of the respondents spent 5,001 to 7,500 Naira (USD33 to 50) monthly for internet use. The scientists believed that the internet has enhanced their academic activities by generally holding very positive opinions on the contribution of internet to their job performance. The major constraints faced by the scientists in using internet were the epileptic power supply with 60.0 per cent response followed by slow internet connection/speed (57 per cent) and inadequate institutional internet facilities (49.1 per cent). The findings of the study have revealed the need for the university to improve on its internet infrastructures and effective user education among the scientists for the maximal benefit from utilization of internet. Practical implications -This study contributes to the body of knowledge in expanding the literature on internet use. It has also profoundly contributed to policy making and planning and it has indicated the need for the university policy makers to provide internet access for the scientists in their offices, library and e learning centres. Originality/value -This paper has provided useful empirical data on the usage of internet by the scientists in OOU, Ago Iwoye. The results of this study should assist the university management and the library administrators in OOU and also other universities in the country on how to improve on the provision of internet services.