Advances in Information and Communication Technology have significantly affected the way information is acquired, processed, stored, retrieved, communicated as well as secured. This has changed the way Librarians handle and secure information systems while users are expected to have some level of information and communication technology skills to access and utilize information systems to their full benefits. This study investigated the influence of tech-skills of librarians and users in securing the information systems of selected Nigerian University libraries, employing multiple regression as well as mean and standard deviation involving a survey of 48 librarians and 44,508 registered users of purposively selected university libraries in South-west Nigeria. The study established that most librarians have basic information technology skills but are poor at advanced skills, furthermore, library users also have basic IT knowledge and skills but most users are fairly skillful at advanced information technology. Basic information technology skills of librarians did not significantly influence information systems security, whereas advanced information technology skills does. On users basic information technology skills, there is significant inverse influence on information systems security while advanced information technology skills of users had significant positive influence on information systems security. The result also revealed that there was significant joint influence of basic and advanced information technology skills of librarians and users on information systems security. The study concludes that it is pertinent that librarians have advance skills in order to ensure secure information systems. The paper recommends structured training and capacity building initiatives to re-tool and up skill librarians.