The study investigates neural processing underlying the perception of vanillin and structurally similar odorants, vanitrope and vanillyl ethyl ether (VEE), aiming to discern subtle differences in odour perception using functional magnetic resonance imaging (fMRI). Despite similar psychophysical ratings of intensity, pleasantness and familiarity for the odours, fMRI analysis with 44 individuals revealed distinct activation patterns in brain regions associated with olfactory processing, memory retrieval and odour recognition. Specifically, increased activations were observed in the parahippocampal gyrus and left amygdala during the perception of vanillin compared to vanitrope and VEE. This indicates a link between emotional responses and familiarity, particularly in the case of vanillin, which evokes a well-established association with the recognisable scent of vanilla. Results from further analysis could imply that the orbitofrontal cortex is involved in the differentiation of odours, especially in forming associative links between vanillin and the commonly recognised vanilla aroma, while the hippocampus might be involved in consolidating odour-induced memories. The findings underscore the intricate interplay between olfactory perception, emotional processing and memory consolidation within the human brain. The study demonstrates the utility of fMRI in elucidating subtle perceptual differences in similar odorants and sheds light on the underlying neural mechanisms governing odour discrimination and recognition.