Introduction: Obesity and overweight are global epidemics, affecting more than one third of the world's population and their impact on workers' activities are evaluated in occupational medical examinations. Objective: To determine the relationship between obesity and occupational medical unfitness of workers in construction companies in Lima between the years 2011- 2017. Methodology: Analytical cross-sectional study, developed in Lima through the review of the results of pre-occupational examinations performed in several medical centers for construction companies for various job positions. Association statistics were obtained for the multiple associations of aptitude according to the obesity of those evaluated. Results: Of the 6398 pre-occupational examination results. Those with some degree of obesity had unsuitability percentages exceeding 97%. There were differences in fitness among those who were overweight or obese according to age (p<0.001), total cholesterol (p<0.001), HDL choles terol (p<0.001), LDL cholesterol (p<0.001), triglycerides (p<0, 001), glucose (p<0.001), systolic pressure (p<0.001), diastolic pressure (p<0.001), stress tests (p<0.001), EKG (p=0.001) and musculoskeletal test (p<0.001). Conclusion: Workers of construction companies in Lima who suffered from obesity were more related to an assessment of occupational medical unfitness during the period 2011-2017.