The remobilized Pre-Neoproterozoic and juvenile Neoproterozoic systems of the Western Ethiopian Shield consist of three N-S trending terrains. These are the western migmatitic gneissic terrain(WMGT), the central meta-volcano-sedimentary terrain(CVST), and the eastern migmatitic gneissic terrain(EMGT). The CVST contains a suture zone of ultramafic-metasedimentary complexes in its eastern half, whereas metavolcanics predominate in the western half. The CVST and its adjacent areas often contain syn- to post-tectonic gabbroic to granitic intrusions. The petrography and major and trace element compositions of intrusions in and around the CVST in the Ghimbi-Nedjo area were examined to determine their petrogenesis and the tectonic setting in which they were emplaced. The Bikilal-Ghimbi, Gombo Kora, and Daleti gabbros intruded within the EMGT do not preserve melt composition. In contrast, the Senbet-Dura and Gebeya-Kemisa diorites that were intruded in the boundary between WMGT and CVST, the Wayu-Meni gabbro in the CVST metavolcanics, and the Kemashi diorite in the CVST suture zone all preserve primary melt compositions. Multi-element plots indicate that all the intrusions in the CVST metavolcanics and the boundary between the WMGT and CVST have arc-type and back arc basin-type magma affinities, showing enrichment in large ion lithophile elements and Nb-Ta depletion. Conversely, gabbros from the EMGT and one diorite body in the CVST suture zone have ocean island tholeiite (OIT)-type magma affinities. These two contrasting magma types intrude geologically differing units bordered by the ultramafic-metasedimentary suture zone. This suggests that accretion/intrusion of arc-back arc type plutons and OIT-type plutons occurred near the suture zone. Such a magmatic association is common in the Arabian-Nubian-Shield(ANS), and is interpreted to have formed in intra oceanic, convergent margin, and continental collision settings, with subsequent preservation along the suture zone in the Neoproterozoic. The West Ethiopian Shield thus formed as a part of the ANS during multi stage accretion and closure of the Mozambique Ocean in Neoproterozoic time.