This study analyses the sources cited in 32 post graduate (Master and PhD) theses in sociology and economics at University of Peradeniya submitted between 1996 and 2014. The objectives of this citation analysis were to find out the types of cited documents, the chronological distribution and authorship pattern of cited documents in the fields of sociology and economics, and to compare them. Citations were chosen from the title pages and the lists of references of each dissertation were examined. Data included the year of submission of thesis, source of citations, age of materials cited and types of authorship. Citations to journals were further analyzed to examine their authorship pattern, research collaboration, geographical location and check the applicability to Bradford Law of scattering. Results revealed that both sociology and economics authors cited mostly books, which proved previous studies that found social science disciplines cited books mostly than science disciplines. Citations in both sociology and economics were almost entirely of English language sources. Economics scholars cited latest materials than sociology scholars did. The results indicated that sociology literature is scattered among various subjects than economics. There is no significant difference between the citation behavior of sociology and economics scholars of University of Peradeniya except some differences in chronological distribution and research collaboration. Understanding the citation behavior of sociology and economics scholars will help librarians to formulate pragmatic policies and making decisions on collection development.