We demonstrate the creation of a transient spin-polarized current grating in bulk GaAs at room temperature. The spin current is injected through quantum interference between two-photon absorption of fundamental (1.55 µm) and one-photon absorption of second harmonic (775 nm) pulses. Because the fundamental and second harmonic pulses do not propagate collinearly, a spin current grating is formed, which decays by electron diffusion.