This article analyses the stagnation of productivity and the increasing structural heterogeneity of Mexican manufacturing industry in the period 1994-2008. Traditional indicators of dispersion are estimated for 200 activity classes, 50 branches and nine divisions of the manufacturing sector; and these corroborate the widening disparity in productive efficiency between globalized activities and traditional industries that has been reported in other papers. The study also provides a more detailed account of the intensification of this trend in the first decade of the present century and the specific characteristics of within-sector heterogeneity. Other results obtained using a shift-share technique show that structural change contributes very little to productivity growth, and that technological progress is concentrated in just a few activities that engage with the domestic economy in a variety of ways. Nonetheless, these activities have weak local linkages and add little value to the content of the goods they make.