The study investigates whether individuals can effectively monitor errors and make adaptive adjustments following acute sleep deprivation. Thirty-three university students (16 males and 17 females) performed the Flanker task before sleep deprivation (pre-SD), after 24 h of sleep deprivation (SD-24), and after 36 h of sleep deprivation (SD-36). An electroencephalogram (EEG) was used to collect error-related negativity (ERN) and error positivity (Pe) components, which index error detection and error awareness, respectively. Verbal reports were also employed to measure error awareness. Results showed that post-error slowing effects were present in all three conditions, with the smallest effect observed at SD-24. Post-error improvement in accuracy was only evident at SD-36. Error awareness was lowest at SD-24, with no significant difference between SD-36 and pre-SD. The Pe amplitude significantly reduced at SD-24. The study shows that post-error slowing effects persist following acute sleep deprivation, and post-error adjustments do not decline further with longer deprivation but instead show some recovery. The findings provide empirical evidence for post-error adjustments after acute sleep deprivation and support the existence of neural compensatory mechanisms.