The present study analyzes and discloses the impact of base salary contribution in determining the amount of pension severance at old age and disability insurance, that covers the Law of the current Social Security for each case, is studied also causes the lack of knowledge of Social Security benefits by the workers. This requires a mixed methodological approach supported in the qualitative tradition of case study aimed to particularization and not generalization, which made it possible to link the obtained data with the theory, and to describe, analyze and explain the results found with the object of study. The results emerged from the application of the survey conducted with 22 items, whose questions were closed and structured with the method of Likert that were answered by 40 workers at two companies known as SMEs in the City of Culiacan, Sinaloa, Mexico, during the month March 2014. On completion of the analysis of the data collected, the results show a severe deterioration of pensions due to low wages and lack of jobs and declining resources with the new pension system of pensions and from the workers an almost total ignorance of the benefits that the law provides motivated by the lack of diffusion by the IMSS and the lack of enterprise training.