Objective: To determine the socio-labour factors associated with variation in BMI and waist circumference in workers in 15 Peruvian cities. Material and Method: A secondary data analysis was performed, in which BMI and waist circumference were associated to the work period (less than 1 year, up to 5 years, up to 10 years, up to 20 years and more than 20 years), sex, age and type of worker. Results: According to the multivariate analysis, BMI was associated with male sex (p<0.001 value) and with increasing age (p<0.001 value). On the other hand, waist circumference was positively associated with working periods of up to 5 years (p-value: 0.015), up to 10 years (p-value<0.001) and up to 20 years (p-value: 0.003), as well as with increasing age (p-value <0.001). Conclusion: It was found that sex and age were related to BMI variation, whereas work period and age were associated to waist diameter.