HRD is extensively concerned with human capital investment, but only focuses on how skills and knowledge become obsolete to a limited extent. In this paper we look at the speed of obsolescence. Using data from a survey among Dutch public sector employees, we find that the yearly rate of skills obsolescence is 2.6%. Subsequent analyses show that the skill obsolescence rate is impacted by educational attainment level, occupation, and sector of employment. (Contains 4 figures and 1 table.)