This paper examines the relationships between the administrative functions of planning, organizing, staffing, coordination and physical facilities and postgraduate theses availability in universities in south-south zone of Nigeria. Five null hypotheses were tested in this study at 0.05 level of significance. A sample of 169 librarians and library officers and 44 postgraduate school administrators were randomly selected from five universities within the south-south zone of Nigeria. Two survey instruments were used for the study namely: Librarians' and Library Officers' Questionnaires (LALOQ) administered on librarians and library officers and Theses Collection Attribute Descriptive Scale (TCADS) administered on postgraduate school administrators. Pearson Product Moment Correlation Analysis was used in testing the hypotheses. The study found that staffing, physical facilities, coordination and planning have significant relationship with postgraduate theses availability in universities in south-south zone of Nigeria. It was recommended that adequate attention be paid to planning, organizing, staffing and coordination functions as well as the provision of adequate physical facilities by university librarians to make postgraduate theses readily available to users in universities in the south-south zone of Nigeria.