Berries are widely recognized for the presence of phenolic compounds (PC), especially anthocyanins. Solid–liquid extraction of PC with different solvents from vegetable sources is the most commonly used techniques for isolating these compounds. This work is the first attempt to evaluate the influence of the solvent used in the extraction of PC from black mulberry (Morus nigra), blackberry (Rubus ulmifolius) and strawberry (Fragaria x ananassa) cultivated in southern Brazil. Three different organic solvents were used for the extraction (methanol, ethanol and acetone) and distilled water (H2O). Different organic solvent-water mixtures were also used (70:30, v/v and 50:50, v/v), as well as organic solvents with acetic acid (99.5:0.5, v/v) and organic solvent-water mixtures with acetic acid (70:29.5:0.5, v/v/v and 50:49.5:0.5, v/v/v). Thus each berry was extracted in nineteen solvent systems. The total phenolic content (TPC) and anthocyanin content (ACC) of the extracts were evaluated, as well as their antioxidant capacity using FRAP, DPPH• and ORAC assays. For all the berries analyzed, acetone:H2O (70:30) was the most efficient solvent in extracting PC and methanol:H2O:acetic acid (70:29.5:0.5) had the best values for ACC. In which, black mulberry had the best result for TPC (5744.55 mg gallic acid equivalents 100 g-1 dry weight (DW)) and ACC (3692.19 mg cyanidin-3-glucoside equivalents 100 g-1 DW). Extracts using ethanol:H2O:acetic acid (50:49.5:0.5), acetone:H2O:acetic acid (70:29.5:0.5) and acetone:H2O (50:50) presented the highest antioxidant capacity for black mulberry, blackberry and strawberry, respectively. In summary, our results showed that the extraction of antioxidant compounds is significantly affected by solvent systems.