This study aims to contribute to the better understanding of how voluntary-based policy intervention has affected the farm structure, especially the evolution of on-farm labour. The analysis on the relationship between farms that participated in agri-environmental measures (AEMs) and evolution of their on-farm labour is investigated during the period 2004–2014 with using Slovenian Farm Accountancy Data Network (FADN). More specially, the relationship between AEMs and hired labour use is explained by farm size and farm type divisions. The results of statistical analysis give evidence that hired labour use is positively correlated by AEMs in all farm size classes. Regardless of farm size, increase in the demand for hired labour use in AEM adopted farms could be explained by the requirements of environmental farming practices that are often more labour intensive than the traditional farming practices. Farm type division analysis reveals that the correlation between AEMs and hired labour use is significantly positive, depending on the farm type. For field crop farms, we observe a weak correlation between AEM payments and total labour use. This could explain with the application of AEM practices do not necessary perceived the hired labour use as a complementary to family labour by filed crop farm managers.