ABSTRACT. – Monthly samples of macrobenthic fauna (> 1 mm) were collected during two hydroperiods (from November 1997 to July 1998 and from November 1998 to July 1999) from permanent waters of the Empordà salt marshes (NE Iberian Peninsula). During the summer of 1998, a severe drought took place at the sampling site. A significantly higher diversity was found after the severe drought, caused by a decrease of the dominant taxa (Nereis diversicolor and Corophium orientale) and the appearance of taxa which were not found before, such as Ephydridae species. Before the severe drought, the macrobenthic community was dominated by the Mediterranean endemic amphipod Corophium orientale, which almost disappeared after the severe drought. The decrease of the population of Corophium orientale coincided with an increase of more opportunistic taxa, such as some Paranais sp. and Streblospio shrubsolii. The population of C. orientale had three abundance peaks (more than 6000 ind·m^-2) during the first hydroperiod, before the severe drought, and none of such magnitude during the second hydroperiod. In contrast, the severe drought did not imply differences in sex ratio dominance, which was dominated by females both before and after the severe drought in the bigger length-classes and in most of the sampled dates. Moreover, no body size differences were detected before and after the severe drought.