A laboratory study was carried out to assess the suitability as soil amendment of a sludge obtained through aerobic depuration of wastewaters from a winery ('winery-sludge'). During a 180-day incubation period, changes in chemical and biological properties of a soil amended with 0.5 and 2.5% of sludge were evaluated. At the end of the experiment, winery-sludge increased the amount of available N, P, K and S, organic and potentially mineralizable carbon, and total microbial activity, while pH, biomass C, dehydrogenase activity, decomposition rate, water-soluble sugars, phenolic compounds and chemical oxygen demand (COD) were not affected by the sludge application. A germination test indicated that the winery-sludge did not show toxicity even immediately after its addition to soil. The great build-up of salinity in soil amended with the highest dose could give rise to risks to crops and environment, so there is a need for field tests.