In this article the relationship between higher level employees' age and assessments of professional expertise is described. Hypotheses have been tested with original survey data from 417 higher level employees and 224 direct supervisors. Concerning the analyses of the effects of age, our hypotheses have for the greater part been confirmed. In our study, we have found that age-related stereotyping is an important phenomenon where assessments concerning professional expertise are made by supervisors. As regards the self-ratings, there is no relationship between age and professional expertise. Further research is needed to understand the pattern of differences between the two types of ratings. Some speculations concerning improvements of the measurements are discussed.