RationaleThis article shows that labour market flows – between employment and unemployment and economic inactivity, and between jobs – vary appreciably across age groups. It also explores the impact of population ageing on aggregate labour market flows in Spain.Takeaways•Labour market flows – between employment and unemployment and economic inactivity, and between jobs – testify to greater mobility among younger workers.•Consequently, with all else being equal, the ageing of the employed population in Spain in recent decades appears to have been one of the factors behind the considerable reduction in aggregate flows in the Spanish labour market.•In this setting, as population ageing will foreseeably intensify in the near future, the labour retraining processes already under way as part of firms’ digital and green transitions will likely encounter difficulties.