The aim of the present study was to analyze the heart rate variability (HRV) and the electroencephalographic (EEG) power spectrum in low and high performance chess players during easy and difficult chess endgames. A total of 28 chess players participated in this cross-sectional study. Participants were divided into two groups according to their ELO level (rating system used by the international chess federation): 1) high level chess players (more than 1600 of ELO score); and 2) low level chess players (ELO less than 1599 of ELO score). Chess players had to complete two easy and two difficult endgames while the electroencephalographic activity and heart rate variability were assessed. High level chess players exhibit more alpha EEG power spectrums (p-value>0.05) during difficult than during easy chess endgames in the occipital area (O1 and O2 electrodes). Moreover, high performance players showed a reduced autonomic modulation (p-value>0.05) during the difficult chess endgames which low performance players did not reach. These results could suggest that high level chess players adapt their neurophysiological response to the task demand.