The study’s general purpose is to assist both management and collection development practitioners in adopting appropriate strategies for integrating OA materials into libraries collections. The study was designed to specifically examine the challenges to the integration of OAR into libraries collections and to explore relevant strategies for the integration. The study utilized an online survey questionnaire sent to Seventy Eight collections development staff drawn from academic libraries, Library Boards, and special libraries for completion. Sixty Two (62) however, were completed and returned. This implies 79.4% return rate. All the respondents surveyed are members of the Nigerian Library Association (NLA), and are certified by the Librarians Registration Council of Nigeria (LRCN). The respondents were drawn from Federal university Libraries (7), State university libraries (6), private university libraries (22), federal polytechnic libraries (5), state polytechnic libraries (12), college libraries (5), special libraries (2), library boards (3). The survey instrument included Eleven (11) items. Data were analysed using graphical charts. The findings indicate that majority of the library do not acquire OAR, but have plans to make them part of their regular library acquisition workflows; majority of them strongly agree that collection development policy is key to OAR integration, but they don’t have the document for now, neither are their staff trained to manage OA effectively. Their major challenge to OAR integration include poor electricity supply, lack of knowledge and skills required for OA integration, and lack of support from the head librarian, lack of collection development policy document. The recommendations include that collection development policy should be put in place; library staff should be equipped with relevant skills through training and retraining; libraries should rather than purchasing expensive books and journals download OAR relevant to them, process them and make them available to their users as part of their collections; Libraries should be provided with uninterrupted fast speed internet access and power supply from solar power.