It is well known that rainfall causes soil erosion in sloping German vineyards, but little is known about the effect of age of plantation on soil erosion, which is relevant to understand and design sustainable management systems. In the Ruwer-Mosel valley, young (1- to 4-years) and old (35- to 38-years after the plantation) vineyards were selected to assess soil and water losses by using two-paired Gerlach troughs over three years (2013–2015). In the young vineyard, the overland flow was 107 L m–1 and soil loss 1000 g m–1 in the year of the plantation, and decreased drastically over the two subsequent years (19 L m–1; 428 g m–1). In the old vineyard, soil (from 1081 g m–1 to 1308 g m–1) and water (from 67 L m–1 to 102 L m–1) losses were 1.2 and 1.63 times higher, respectively, than in the young vineyard.