Blackberry has an important potential in fruit species because it is commonly used in both the fresh and processing market. In the present study, the organic acid (citric acid, malic acid, succinic acid, and fumaric acid) and sugar (fructose, glucose, and sucrose) contents of the blackberry genotypes grown in Van province of Turkey were determined. Organic acid and sugars are among the criteria in fruit maturation as well as they are effective in several physiological events. The citric acid was the predominant organic acid in the studied blackberry genotypes and ranged from 5.690 to 12.019 g/kg. The citric acid was followed by malic acid which varied from 1.412 to 6.346 g/kg. While the genotype 65ED02 had the highest total organic acid content (20.827 g/kg), the genotype 65ER01 had the lowest total organic acid content (8.469 g/kg). Fructose was the predominant sugar in the studied blackberry genotypes and ranged from 11.272 to 25.241 g/kg. While the genotype 65ED01 had the highest total sugar content 44.399 g/kg), the genotype 65GV01 had the lowest total sugar content (22.117 g/kg).