This study assesses the extent to which durum and bread wheat high yielding varieties (HYVs) have been adopted by farmers in northern Tunisia, a region which accounts for more than 80 degrees ' of the nation's durum wheat production and close to 90 percent of its bread wheat production. Estimates are presented of the areas grown to various HYVs by agroclimatic zone and farm size. The adoption history of each wheat HYV is outlined, including its date of release, its peak adoption, an (if applicable) its disadoption. The impact of HYVs is discussed; particular attention is devoted to genetic yield gains, impact on farmers' income, and impact at the national level.vi, 28 pages