Abstract: The invention relates to a piece of furniture having a convertible work surface, comprising: a lower frame (1) suitable for supporting a surface on which a fixed part (3) is arranged, said part having a series of concave curved faces (31) on its periphery; and a number of mobile parts having at least one convex curved face (41) and two straight faces (42, 43) on the periphery thereof, said straight faces being arranged perpendicular to one another. The mobile parts (4) are provided with means for arranging same in relation to the lower frame (1), in: a first operating position in which the mobile parts (4) are arranged around the fixed part (3), defining, together with the fixed part (3), a first work surface (51) in the shape of a polygon, rectangle or quadrangle; or a second operating position in which the mobile parts (4) are arranged on top of the fixed part, abutting along their straight faces (42, 43), said mobile parts (4) defining a second work surface (52) of a circular or oval convex curved shape.