This dataset contains data used in the research described in the paper entitled ‘Contrast and Conflict in Dutch vowels’ by De Rue and colleagues (2021), published in Frontiers of Neuroscience. Data was collected to test neural discrimination indicating perceptual discrimination of Dutch tense mid vowel pairs /o/-/eu/ (place contrast), /e/-/eu/ (labiality contrast. , and /e/-/o/ (place and labiality contrast). Electrical brain responses to vowel changes were measured through EEG in a passive oddball paradigm. Vowels were auditorily presented over headphones and the automatic brain response recorded. Participants watched a silent movie throughout the experiment. There was no overt task. Data were collected to measure the Mismatch Negativity (MMN) response to vowel changes in order to gain insight into the phonological representations of these Dutch vowels that have not been investigated before. 18 adult native Dutch participants were tested. Data were analyzed using BESA. The data collection contains: raw data of EEG recordings for 18 adult native Dutch participants: files with extention .eeg contains actual EEG recording, files with extention .vhdr is a header file containing information about the EEG recording such as number of channels, amplifier settings etc., and files with extention .vmrk with marker information). Data is recorded using Brain Vision Recorder. Data is named with a participant identifier code, for example pp03 refers to participant number 3. Data is completely anonymous.