This study uses panel data to examine the relationship between faculty employment and external R&D expenditures at Research and Doctoral institutions over a 15-year period of time. On average, a 1% increase in the number of full-time faculty is associated with about 0.2% increase in total R&D expenditure. Further, a one percentage point increase in the share of full-time faculty members that are not on tenure-track lines is associated with a decrease in total external R&D expenditure by about 0.6%, suggesting that full-time faculty that are tenured or on tenure-tracks are the main category of faculty that generate external R&D funding. Further, our results suggest that an increasing usage of part-time faculty, holding constant the institution's full-time faculty size, boosts an institution's external R&D expenditures. On average, a one percentage point increase in the share of part-time faculty members is associated with a 0.44% increase in the total external R&D expenditures. Increases in graduate student enrollments are associated with increases in external R&D expenditures. Finally, an institution's external R&D expenditures are significantly influenced by both the amount of its own institutionally financed research expenditures and the level of federal funding for research. (Contains 5 tables.)