The study investigated developmental policies as determinant of preservation of library resources in tertiary institutions in Cross River State, Nigeria. Specifically, it focused on finding out whether selection and acquisition had any relationship with the preservation of library resources. Two research questions and two statements of hypotheses were posed to guide the study. Conceptual, empirical and theoretical studies were reviewed based on the variables in the study. A survey research design was adopted for this study. Four hundred and two (402) librarians working in tertiary institutions in Cross River State formed the population of the study. The instrument used for data collection was a 30-item questionnaire named the Development Policy as Determinant of Library Resources Preservation Questionnaire (DPLRPQ) constructed by the researchers. Pearson product-moment Correlation analysis was the only statistical tool used in testing the hypotheses at 0.05 level of significance. The study's findings revealed a significant relationship between the selection, acquisition, and preservation of library resources in tertiary institutions in Cross River State. I was recommended, among others, that the Government of Cross River State should adequately fund tertiary institution libraries to enable the acquisition of facilities and devices for adequate organisation and preservation of library resources.