This study examines the exchange of citations between two disciplines -- Educational Technology (ET) and Library and Information Science (LIS) -- as an indication of their interdisciplinary impact. The study was conducted in three phases. The first phase consists of an analysis of citations from ET journals to 15 top LIS journals; the second phase examined citations from LIS journals to 15 top ET journals; the third phase studied the five LIS journals -- not on the original list of 15 -- to cite ET journals and the relationship of citations from ET journals to them. The findings of this study reveal that about 1/10 LIS articles and 1/30 ET articles in the study sample were cited at least once in an article from the other discipline. This suggests that LIS has slightly stronger impact on ET research than vice versa. Among specific journals, the Journal of Education for Library and Information Science and the Journal of Documentation in LIS and Educational Technology Research and Development and the Journal of Educational Technology and Society in ET were most cited in the other discipline. Overall, the findings indicate a fair amount of exchange of ideas between the disciplines of LIS and ET. These findings are significant for interdisciplinary researchers in both ET and LIS as an indication of the links between and impact of these disciplines.