This paper presents an electrical analysis of external mechanical stress effects on devices characteristics for long and short channel MOSFETs in advanced 0.13 mum technology. Similar bulk and SOI generations for nMOS and pMOS devices are studied. By applying external calibrated stress we measure piezoresistive effects and compare small and long transistors electrical responses. Main results are that the threshold voltage (V-t) variations were shown negligible whereas mobility dependence with stress was the most significant effect. After the parasitic series resistance (R-sd) correction on short devices, we extracted comparable piezoresistive coefficients on short and long devices indicating that 2D or local effects can be neglected in all cases. Comparison bulk/SOI showed slightly higher piezoresistive coefficients for SOI. Finally, measurement errors were estimated. (C) 2003 Elsevier Ltd. All rights reserved.