Oats are increasingly popular due to their healthiness, and the number of new different types of oat products on the market is constantly increasing. Oats have higher content of lipids compared to many other grains and therefore their quality and volatile compound profile is susceptible to changes. In this study, selected oat samples were investigated using HS-SPME-GC-O panel and trained sensory panel in order to identify the compounds contributing to the odour characteristics. GC-O panel was trained to describe odours and to evaluate odour intensities of oat samples as flour-water mixtures. The odour and flavour characteristics of the same oat samples were characterised using a sensory panel using generic descriptive analysis. The GC-O panel detected 30 odour-active compounds. The most often described compounds were aldehydes, such as hexanal described as ‘green’ and ‘grassy’, or 3-methylbutanal described as ‘chemical’ and ‘pungent’. At the same time, little differences were observed in ‘green odour’ by the sensory panel, whereas more differences were observed in bitter taste and odour and flavour intensities.