The paper examines patterns of self-citation in six disciplines distributed equally among the physical and social sciences and the humanities. Sample articles were examined to determine the relative numbers and ages of self-citations and citations to others in the bibliographies and to the exposure given to each type of citation in the text of the articles. Significant differences in the number and age of citations between disciplines were found. Over all, 9% of all citations were self-citations; 15% of physical science citations were self-citations, as opposed to 6% in the social sciences and 3% in the humanities. Within disciplines, there was no significantly different amount of coverage between self-citations and citations to others. Over all, it appears that a lack of substantive differences in self-citation behavior is consistent across disciplines. The number of words devoted to self-citations vary among disciplines, but remain constant within a discipline for both self-citations and citations to others.