The HHA launched an effort to gather, record and translate hydrotechnical terms, in order to create a scientific dictionary covering all disciplines of hydraulic science. The first version of the dictionary (which appeared in December 1997) was the result of collective work, undertaken by a working group.The 10th volume of the “Hydrotechnica” journal is a special issue including an updated version of this Dictionary. We hope that the members of our Association, who cover a large scientific spectrum, will contribute to the correction of any mistakes and to the inclusion of more terms, in order to continuously upgrade this useful dictionary.