The Pessegueiro Island Marine Protected Area (MPA), SW coast of Portugal, was implemented in 2011 with the purpose of protect biodiversity and prevent over-exploitation of commercially important fish species. Amongst those species are the Mediterranean moray (Muraena helena) and the European conger (Conger conger). In this context, the aim of this study was to assess the importance of this MPA as a refuge/feeding area for these species and to evaluate its location and size adequacy. The study was carried out during the summer of 2013 and a total of 19 morays and 6 congers were tagged with acoustic transmitters. An array of 19 automatic receivers was deployed with a sampling design that spatially covered the entire MPA. The data from the receivers was analysed through multivariate statistics (PERMANOVA), Kernel Density Estimation (KDE) and Network Analysis. Results showed that the Pessegueiro Island MPA is an important zone for both species since the tagged morays and congers spent 48% of the time within the area (average residency index). Also, KDE and Network Analysis showed that both species displayed relatively reduced home ranges, 20 ha in average for morays and 30 ha for congers, and the movements performed were limited to adjacent areas. Activity was more intense during night time for both species. Regarding morays, lunar cycle and sea conditions also seemed to influence their movement patterns. The data collected in this study highlight the importance of this MPA for the target species.