This paper is the first attempt to study the recruitment of Serpuloideans in a Mediterranean marine cave through the use of artificial substrates placed in three different positions, from the entrance to the interior of the cave. This study provides qualitative and quantitative data concerning Serpuloidea recruitment on panels removed successively after one, three, six and 12 months of permanence in the cave. A homogeneous distribution of juveniles Spirorbidae throughout the cave axis had already been detected after one month of panel immersion. Spirorbids were recorded also on panels removed after three months as well as serpulids, which began to be detected during this sampling time, even though represented by just one species. A significantly different pattern of distribution throughout the cave axis was observed after only six months, while other serpulids were detected for the first time. The pattern of species distribution seemed to reflect the biotic and environmental conditions of the cave. The highest serpuloidean species abundance and diversity was found on panels placed in the intermediate position within the cave. After only one year of panel immersion, a total of 20 taxa (11 Serpulidae and 9 Spirorbidae) was recorded, including five species listed for the first time in the marine caves of the Salento Peninsula.