Soil erosion in vineyards is considered as an environmental concern as it depletes soil fertility and causes damage in the fields and downstream. High soil and water losses decrease soil quality, and subsequently, this can reduce the quality of the grapes and wine. However, in specialized journals of viticulture and enology, soil erosion studies are not present. This paper surveys the soil erosion losses in the vineyards of Celler del Roure, Eastern Spain, as an example of Mediterranean vineyards. We applied rainfall simulation experiments (10 plots) using a small portable rainfall simulator and 55 mm h−1 in one hour to characterize soil erodibility, runoff discharge, and soil erosion rates under low-frequency-high-magnitude rainfall events at different positions along the vine inter-row areas. We found that 30% of the rainfall was transformed into superficial runoff, the sediment concentration was 23 g L−1, and the soil erosion rates reached 4.1 Mg ha−1 h−1; these erosion rates are among the highest found in the existing literature. We suggest that the vineyard management should be improved to reduce land degradation, and also should be shifted to sustainable agricultural production, which could improve grape and wine quality.