This paper presents a Multi-Subband Monte Carlo study of the drain current improvements in uniaxially, compressively strained (0 0 1)/[1 1 0] p-MOSFETs and analyzes the ingredients through which the strain improves the long channel mobility as well as the I ON of nanoscale transistors. We first discuss the strain induced mobility enhancement and then address the effects of the strain on the I ON. In particular, our results show that compressive stress in (0 0 1)/[1 1 0] p-MOS transistors increases the I ON by improving both the injection velocity and the back-scattering coefficient and that, furthermore, the back-scattering coefficients of the p-MOS transistors have values comparable to those of n-MOS devices with similar channel length.