This study examined availability and use of digital reference tools in private university libraries in south-east Nigeria. It is designed to ascertain the extent of use of DRS tools by Librarians in effective service delivery to users. Survey design was used for the study and 46 respondents comprising of Librarians and Library Staff who directly provide reference services in the private university libraries participated in the study. An observation checklist and a structured questionnaire were administered to the respondents. Data collected was analyzed using descriptive statistics. The study found that email services, text based/instant messaging, online pathfinders and mobile reference service were the most popular digital tools available in the private university libraries. It found that while some tools are being utilized to a very high extent and high extent, other are utilized at a low extent and not used at all. It also found paucity of funds among others as some of the challenges encountered in proving DRS. It shows that provision of funds, regular power supply are some of the strategies that can be adopted at effective provision of DRS. The study concludes by recommending adequate provision of DRS tools in the university libraries for effective service delivery.