The aim of the present study was to investigate whether error detection and subsequent regulatory processes could be influenced by pre-familiarisation with task-relevant stimulus features. To this end, nineteen healthy adults performed a speeded Go/NoGo task with compound targets, involving two concurrent stimulus attributes, which were either prefamiliarised or not, while high-density EEG was recorded. During the speeded Go/NoGo task, response errors clearly elicited an error-related negativity (ERN) and error positivity (Pe), but these error-related components were not modulated by familiarisation. By comparison, post-error adaptive processes were found to depend on familiarisation, as distinct topographic ERP effects were evidenced for familiarised vs. non-familiarised stimuli. Moreover, post-error slowing was abolished in the condition comprising familiarised attributes. These results suggest that prefamiliarisation with a stimulus property leaves unaffected error detection mechanisms, while altering subsequent adaptive processes. Whereas error detection mechanisms may be generic, the automatic adaptive processes consecutive to error detection may be malleable, and influenced by pre-familiarisation of stimulus features.