Polyvinyl chloride (PVC) is one of the most widely used polymers, which contrasts with the low amount of literature on the leaching of associated additives and in particular unintended oligomers, a class of non-intentionally added substances (NIAS). This study sheds light on the occurrence of vinyl chloride oligomers (VCOs) in a variety of PVC analytical standards (n = 4), PVC items employed for construction, medical or food contact applications (n = 14), as well as in foodstuffs and environmental matrices (n = 10). Samples were analysed by liquid chromatography coupled to high-resolution mass spectrometry hyphenated with chloride-enhanced electrospray ionisation. Series of saturated (