Empirical investigations of citations to and from 150 journal articles published in the field of Information and Library Science (ILS) has enabled cross-mapping of the interdisciplinary evolution of the field. The publications were randomly drawn in six years between 1975 and 2000, with 25 articles each from the selected years. ANOVA tests reveal that although raw counts of self- and extradisciplinary- citations are not significantly different by year, they are different depending on whether it is from or to ILS. Nearly 30 disciplines hold mutual citations with ILS, and Computer Science, Communication, Management Science, Education, and Psychology are among those highly impact disciplines. Visualization further depicts the clustering of the citing and cited disciplines. In general out-degree citations contain richer set of nodes than those of in-degree, but overall, the mapping of the interdisciplinary scope of the ILS field provides convincing evidence for the interdisiciplinary nature of Library and Information Science.