We present single crystal neutron diffraction measurements on multiferroic ${\mathrm{LuFe}}_{2}{\mathrm{O}}_{4}$. Magnetic reflections are observed below transitions at 240 and 175 K indicating that the magnetic interactions in ${\mathrm{LuFe}}_{2}{\mathrm{O}}_{4}$ are three-dimensional in character. The magnetic structure is refined as a ferrimagnetic spin configuration below the 240 K transition. Below 175 K a significant broadening of the magnetic peaks is observed along with the buildup of a diffuse component to the magnetic scattering.