Abstract: A drilling fluid additive is provided including ground olive pulp. The ground olive pulp is prepared by drying olive pulp to remove residual water, and then grinding the pulp to a desirable particle size. The pulp is preferably ground to particle sizes of less than about 1500 microns. In a preferred embodiment, 90 percent of the particles are less than about 100 microns in size and 50 percent of the particles are less than about 30 microns in size. The ground olive pulp can be added to oil or water-based drilling fluids. The preparation and use of waste olive pulp as a drilling fluid additive provides an environmentally safe method for disposing of waste olive pulp.