The study was carried out to examine asynchronous digital tools and continuing professional development of librarians in tertiary institutions in South-South, Nigeria. To achieve this purpose, two research questions and two hypotheses were formulated for the study. The study adopted a correlational research design with stratified sampling and purposive technique was used to collect a sample of 300 respondents who are certified librarians from universities, polytechnics, and colleges of education in South-South geopolitical zone, Nigeria. A 40-item questionnaire instrument titled „Asynchronous digital tool and continuing professional development Questionnaire (ADTCPDQ)‟validated, pilot tested and found suitable was applied for gatherings of data. The data were collected by the researcher with some research assistant. Data collected were analyzed using Pearson product moment correlation on statistics. The result showed that use of emails and participation in new group significantly contributes to continuing professional development of librarians. Based on the findings, it was recommended that tertiary institutions in the south south of Nigeria should provide array of digital communication tools and infrastructural facilities that can enable librarians and other professionals to look-up or log-in to access information desired for learning and professional development and that there is need for continual awareness creation among librarians in tertiary institutions about the availability and viability of these online tools to explore and use for their professional development and practice.