We study the relationship between workforce skills and firm’s productivity using Portuguese data for the period 2006-2018. We use a multi-dimensional index that incorporates worker’s education, age, and unobserved ability to measure workers’ skill. The analysis shows that the average skill of the workforce is positively associated with productivity. However, we find a negative relationship between the dispersion of the workforce skills and the value-added per worker. We also estimate quantile regressions and observe that the positive association between average skill and productivity is increasing across the conditional productivity distribution, while the negative association with skill dispersion is stable.