Purpose – ageing population causes a number of economic and social problems related to changes in the labour market. This study aims to evaluate the effect of the ageing population on the labour force which is the main indicator of the labour market in EU member states. Research methodology – in order to achieve the aim of the study we applied the following methods: i) trend analysis to estimate and present population and changes of labour force over period, and ii) decomposition method to examine the effects of population and labour force structure in terms of age changes on size of labour force. Findings – over the 2003–2017 period volume of the labour force has declined in Romania, Lithuania, Portugal, Latvia and Greece. This negative effect is influenced by both depopulation and structural changes in the workforce, including population ageing. Size of the labour force has increased in 23 countries, but in 11 of them, these positive changes were influenced by the rising of population activity, while depopulation it influenced negatively. Research limitations – research results support the theoretical approach that ageing population may negatively affect the labour market but do not provide ways to solve this problem and this is the implication for further research. Practical implications – the obtained results are useful for policymakers of the labour market (including pension reforms). Originality/Value – the study contributes to scientific literature by sufficient understanding of ageing population problems that occur in labour market and fills the gap in research of ageing population impact on the labour market, using data of EU member states.