This study investigated the role of libraries in sustainable educational development in Niger State. The objectives of the study were: determination of the sustainability of tertiary educational development in Niger State; the role of academic librariesin sustainable development in Niger State, and factorsinhibiting the sustainability of educational development by institutional librariesin Niger State. Three researchquestions were postulated to guide the study while a descriptive survey research method was used for the study. The population of the study comprised 78 educational institutions. As such, 78 copies of questionnaire were administered out of which 70 (90%) were returned and found usable. Descriptive statistics method was used in analyzing the data collected which are shown in tables with frequencies and percentages. The findings of the research showed that production of adequate manpowerand availability of skilled expertswere among the reasons for sustaining education development while availability of well trained teachers and provision of adequate financial resources were among the factors necessary for sustaining educational development in Niger State. The findings of the study also revealed that inclusive selection of relevant, current and adequate information resources both in print and non-print were some of the roles academic libraries could play in sustaining educational development in Niger State. Further more, the findingrevealed that lack of specificskilled manpower and insufficient deployments of Information Communication Technologies were some of the factors inhibiting the sustainability of educational development in Niger State. The study concluded that despite the facts that Niger State has made great impact in the development of the education sector, there is room for more improvement. It is thus recommended, among other things, that proprietors of tertiary institutions should provide sufficient funding to the libraries in theState.