A non-planar tri-gate p-MOS transistor structure with a strained channel region and a non-planar tri-gate integrated strained complimentary metal-oxide-semiconductor (CMOS) structure are described. A relaxed Si1-x Gex layer is formed on the silicon-on-isolator (SOI) substrate. The relaxed Si1-x Gex layer is patterned and subsequently etched to form a fin on the oxide. The compressively stressed Si1-y Gey layer, having the Ge content y higher than the Ge content x in the relaxed Si1-x Gex layer, is epitaxially grown on the fin. The Si1-y Gey layer covers the top and two sidewalls of the fin. The compressive stress in the Si1-y Gey layer substantially increases the hole mobility in a channel of the non-planar tri-gate p-MOS transistor structure.