This paper studies the association between graduation age and earnings among university graduates in Denmark, which is a country with one of the oldest student populations in the world. Exploiting a rich data-set from administrative registers, the current study is able to track labour market career for a longer period of time and to control for more labour market-relevant variables than any previous study of graduation age and earnings. The results show that graduation age has either a slightly positive or an insignificant impact on starting wages within the public sector or a negative impact on starting wages among private sector employees. This applies to both genders, but the differences are stronger among male employees. The analyses of long-term wages reveal a more homogeneous pattern. Mature graduates earn less in all the years investigated. The wage differences are greatest among male graduates employed in private enterprises, and the gap increases throughout their careers.