We present here the results of the first semi-quantitative survey of arachnids conducted on coastal dunes of Spain. We used the optimized COBRA protocol to sample two localities along the Valencian coast. We collected 2886 specimens (58.2% juveniles), belonging to 78 species, 70 genera, 31 families, and 4 orders. The species Larinia chloris (Audouin, 1826) and the genus Cebrennus Simon, 1880 are reported in Europe for the first time. We further confirm the presence in Spain of the spiders Lathys narbonensis (Simon, 1876) and Ariadna inops Wunderlich, 2011. We present images of the diagnostic traits of the most interesting finds along with a checklist of the Arachnida present in the Valencian coastal dunes.