The intense use of agrochemical compounds and mechanisation alter the soil quality. In particular, conventional winegrowing requires a large amount of pesticides which in turn disturbs the biological activities of vineyard soils and subsequently results in soil organic matter losses, changes of chemical soil properties, settling and erosion. Alternative organic wine-growing aims to limit the alteration of soil quality. Generally, organic conversion involves the use of organic manures and pesticides instead of chemicals, promoting grass cover, tillage. These modifications impact on soil biological functioning, but little work has been done to characterise this conversion on vineyard soils. Our objective is to evaluate how nematofauna, used as bioindicator, can be considered as a tool to characterise global soil quality during organic conversion of a vineyard. For this work, 24 plots converted to organic wine-growing since 1980, 1998, 2002 and 2008 were studied at the field scale. Four replicates of soil were sampled in May 2008 for each plot. The first results showed that nematodes were very sensitive to conversion to organic wine-growing. Total nematode abundance was significantly higher in plots that were converted to organic wine-growing the longest (1,672 nematodes per 100 g of soil for a conversion in 1980, against 936 for conversion in 2008). An increase of the proportion of plant parasitic and root hair feeding nematodes was observed from the conversion in 2002. At the same time, there was a decrease of the proportion of bacterial-feeding nematodes and omnivores. In particular some families like Dolichodoridae, Panagrolaimidae, Aphelenchidae and Aphelenchoididae were promoted by the conversion to organic wine-growing.