This study investigates to what extent intangible investments have a positive impact on French wine companies' financial performance. French wine companies are small- and medium-sized enterprises (SMEs), so the task is (a) to measure their intangible expenses and capital, and (b) to estimate their impact on companies' performances. The authors then analyze the effect of property structures (cooperatives and corporations) and business activities on the intensity of the relationship between intangibility and performance. Relationships between intangibles and performance were tested empirically by means of a questionnaire carried out in 2005-2006. Questionnaire data were completed using financial statements for 207 companies whose activity included one or more stages in the production and marketing of wine. Using MANOVA and the production function approach, the authors found evidence that intangible proxies had a negative impact on the firms' economic performance measurements and a positive impact on commercial performance for intermediate values of intangible ratios. They also found that production functions were very different with regard to legal status and business activity, but that the negative impact of intangible proxies remained.