Promising techniques have recently been developed for creating nulls in the transmit sidelobes of a radar by using the signal from a nearby auxiliary antenna. In operational settings, the performance of these nulling techniques will be sensitive to electromagnetic scattering from objects in the vicinity of the antennas. This paper presents a theoretical analysis of the impact of environmental and multipath scattering on transmit nulling performance for a radar system comprised of a main antenna and an auxiliary. A case study example is described for scattering off the ocean surface.