The present invention refers to a base (10) for sewing machines comprising a support structure (14) capable of supporting the fabric to be sewn and comprising a polygon-shaped main plate (16) on which the fabric is placed, a first wing (24) adjacent to the main plate (16) and pivoted in a first side of the main plate (16), and first moving means (30, 38, 40) of the first wing (24) so that the first wing (24) is rotatable about an axis which is coplanar to the main plate (16), and the first wing (24) may be disposed in a first position which is coplanar to the main plate (16) providing continuity of support to the main plate (16), or in a second position which is orthogonal to the main plate (16).