One of the main objectives within the EU-project CLASH (www.clash-eu.org) was to create a generic prediction method for wave overtopping at coastal structures by means of the Neural Network technique. An extensive and homogeneous database on wave overtopping was set up within CLASH, mainly with the aim to be used for the training process of the Neural Network (NN). A total number of 10,532 tests from 163 independent test series were screened and included in the database. The final database consists of far more information than needed for the training of the NN: 31 parameters are included to describe each overtopping test of which only 17 are used for the NN development. This explains the possible use of the overtopping database on its own. Plotting various parameters of the database together in graphs gives a clear view on the contents of the database. Also the ranges covered by the parameters can be detected in this way. The creation of the database, the analysis of the database, and the possible use of the database on its own are described in this paper.