Reconnaissance investigations of outcropping rocks of the western and central Mulgathing Complex reveal a series of pelitic and psammitic sedimentary rocks, interleaved with generally mafic to intermediate composition meta-igneous lithologies. The broad structural geometry of the Mulgathing Complex is defined by a layer-parallel gneissic foliation in all rock types that is deformed by isoclinal early folds and a later open to tight folding generation. These structural features are attributed to the Sleafordian Orogeny. Metamorphic conditions associated with the Sleafordian Orogeny in the western Mulgathing Complex are typically upper amphibolite to granulite facies, indicated by the presence of garnet-bearing migmatites in pelitic lithologies. Lower grade metamorphic conditions are preserved in the eastern and central Mulgathing Complex. Post-Sleafordian reworking is manifest as zones of intense mylonitisation. These mica-defined zones of deformation range from millimetre to kilometre scale, and can be locally recognised as zones of demagnetisation in regional aeromagnetic images. Further work on the geometry, thermobarometric conditions and timing of reworking will assist our understanding of the post-Sleafordian evolution of the Mulgathing Complex.