Introduction - Collection of volatiles from plant roots poses technical challenges due to difficulties accessing the soil environment without inadvertently damaging the roots. This paper describes a novel method for sampling of root volatiles in situ from plants grown under field conditions. Objectives - To validate a new non-invasive method for passive sampling of root volatiles in situ using solid phase microextraction (SPME). Methods - SPME fibres were inserted into perforated PTFE tubes positioned in the soil next to broccoli plants for collection of root volatiles pre- and post- infestation with Delia radicum larvae. Root volatiles samples were analysed by GC-MS. PCA was applied to determine differences in the profiles of volatiles between samples. Results - GC-MS analysis revealed that this method can detect temporal changes in root volatiles emitted before and after D. radicum damage. PCA showed that samples entrained pre- and post-infestation were compositionally different due to the presence of root volatiles induced by D. radicum feeding. Sulfur containing compounds, in particular, accounted for the differences observed. Furthermore, root volatiles emission patterns post-infestation were found to be correlated with the feeding and developmental progress of larvae. Conclusion - This study has demonstrated that volatiles released by broccoli roots can be collected in situ using SPME fibers within perforated PTFE tubes under field conditions. Plants damaged by D. radicum larvae could be clearly distinguished from plants sampled pre-infestation and soil controls on the basis of a number of induced volatiles. These results show that this new method is a powerful tool for non-invasive sampling of root volatiles below-ground.