This paper examines the experiences of five public libraries in adopting and implementing readers' advisory service as an innovation. Using the criteria of allocation of resources, support of library administration, professional status of practitioners and promotion of leisure reading, degrees of implementation are examined. Of the five libraries, one had completely implemented the innovation and started re-inventing it to meet local needs. Three had committed to the innovation, but did not meet all of the criteria that comprised full implementation. One seems to be still in the decision-making stage, and cannot be said to have yet adopted the innovation. The processes followed by each library were grounded in behaviors identifiable through the study of the diffusion of innovations. Understanding of innovation diffusion makes it possible for library administrators and funders to identify and encourage innovative staff members.