Erosion due to concentrated runoff is one of the main problems in the Anoia-Penedes region (Catalonia, Spain). The conventional tillage practices seem to be the reason for the high erosion and runoff observed, together with soil and rainfall characteristics. An experiment was carried out to test cover crop as an alternative management practice. During two years a mixture of legumes and grasses was sown to evaluate the effect on soil losses and vineyard production. Vineyard crop status (leaf water potential, soil water content and final grape yield) and runoff production were measured in three locations. As a result, only a slight reduction of leaf water potential in the vine was found, mostly during the second year. Soil water content and grape yield were not significantly affected by cover crops. The effectivity of cover crops to reduce soil losses was higher in case of highly erosive events during spring, but not at all locations. In autumn there was not enough soil cover to reduce runoff and soil losses. Selective nutrient losses were found, that justify the application of conservation measures.