ObjectivesMental workload is a condition which can negatively influence the overall health of workers. In this study, we aimed to investigate the risk factors for the onset of mental workload, including working conditions, cardiovascular comorbidities and lifestyle habits, in a working population.MethodsThis is a cross-sectional study including 408 workers from a risk prevention service of small/medium companies in Murcia (Spain). Workers from the secondary and tertiary sectors or primary/secondary sectors with administrative management tasks who underwent a routine medical examination between 1 January 2017 and 31 April 2017 were included. Workers from the primary sector and construction were excluded to avoid a sex and age bias.ResultsFrom 408 workers, 206 (50.5%) were females; with mean age 36.8±10.4 years. 164 (40.2%) workers had a moderate to significant risk of mental workload. Based on multivariate logistic regression analyses, independent predictors of mental workload were age ≥30 years (OR 2.42, 95% CI 1.22 to 4.80; p=0.012), working in tertiary (OR 7.89, 95% CI 3.59 to 17.31; p<0.001) or administrative sectors (OR 87.57, 95% CI 35.22 to 217.79; p<0.001) and alcohol consumption (OR 2.08, 95% CI 1.16 to 3.73; p=0.014). Smoking habit (OR 0.47, 95% CI 0.26 to 0.85; p=0.012) was found as a protective variable so non-smoking was considered as a risk factor.ConclusionIn the present study from a risk prevention service including workers of small/medium companies from the secondary and tertiary sectors and workers with administrative tasks, the labour sector, age, alcohol consumption and smoking habits, are independently associated with a higher risk of developing moderate to significant mental workload.