The article investigates the acceptance and perceptions of library practitioners for implementation of library 2.0 applications for information services delivery by University Libraries in Nigeria. Quantitative research methodology, using cross-sectional survey design was used. The population of the study consists of all academic librarians in the university libraries in Nigeria. Questionnaire was the only instrument used to collect relevant data for the study. The findings show that the level of adoption of the library 2.0 among the university libraries in Nigeria was very low. The article also found that perception of the librarians towards the use of library 2.0 was positive. The findings further established that all the library 2.0 tools are personally accepted, used and applied by individual library practitioners for information service delivery, though not officially implemented by most of the university libraries. In general, the study found that the library practitioners had positive perception towards acceptance of the following library 2.0 tools; Blog, ‘Wikis, Instant Messaging’, Twitter, Face book, RSS, YouTube, Podcast, Flickr, Vodcast, etc. The article concludes that the university libraries and library practitioners had varying degree of acceptance of library 2.0 applications for implementation in their libraries. However, the article recommends that university libraries should create and established workshops, seminars and training on the application of library 2.0 to all librarians and practitioners in order to have more awareness and readiness about the use of library 2.0 for its implementation in the university libraries for information service delivery.