espanolEn los anos ochenta se realizaron una serie de trabajos destinados a clasificar morfodinamicamente las playas. Dichas clasificaciones utilizaban fundamentalmente las condiciones energeticas del oleaje incidente, asi como variables propias de la playa, como la pendiente o la velocidad de caida de grano. Posteriormente, a este tipo de clasificaciones se les anadio el efecto de la marea como agente modulador del efecto del oleaje. En el presente trabajo se ha realizado un seguimiento a lo largo de diferentes anos (2000-2004) de mas de 30 playas situadas en el Golfo de Cadiz y en las inmediaciones del Estrecho de Gibraltar. El periodo de estudio utilizado ha permitido obtener tanto morfologias asociadas a condiciones de buen tiempo como aquellas correspondientes a condiciones invernales o de temporal. Las especiales condiciones de esta zona han permitido abarcar rangos mareales variables desde condiciones mesomareales, con rangos cercanos a 4 m, hasta areas de tipo micromareal con rangos inferiores al metro. Por otro lado, la amplia extension de la zona ha permitido analizar playas asociadas a diferentes condiciones de contorno (adosadas, libres, etc�), cercania de los aportes sedimentarios, etc. Sin embargo, todas presentan unas condiciones de clima maritimo mas o menos similares, lo que ha permitido identificar la importancia real que tiene la marea sobre la morfologia del perfil de la playa y por tanto sobre su caracter morfodinamico. Se confirma que el efecto de la marea sobre el oleaje es el principal agente modelador del caracter morfodinamico que presenta una playa EnglishDuring the1980s several attempts were made to classify beaches according to their morphodynamic behaviour. Published papers proposed classifications based mainly on wave incident energy and beach characteristics, such as foreshore slopes and sediment settling velocities. In the 1990s more complex classifications appeared, where the effect of tides on wave action was included, highlighting their relevance to the determination of the morphodynamic state of the beach. In this paper we present a beach monitoring programme, in which more than 30 beaches located along the Spanish shores of the Gulf of Cadiz and the Strait of Gibraltar were surveyed for four years (2000-2004). The long study period allowed the monitoring of beach morphologies related both to fair weather (summer) and storm (winter) conditions. The coastal setting in the study area provided the opportunity for covering a wide range of tidal conditions, from high mesotidal (MSTR ca. 4 m) to microtidal (MSTR around 1 m). Furthermore, the dimensions of the study area permitted the monitoring of beaches linked to different boundary conditions, thus including both attached and detached beaches located at varying distances from main sediment sources, and influenced by different wave regimes. The analysis of the beach morphologies related to such contrasting conditions allowed the identification of the real significance of the tidal effect on beach profile morphology and hence on beach morphodynamics. Finally, we conclude that the effect of tides on wave action is the main factor determining beach morphodynamic behaviour