There is described a folding unit (1) for producing packages (2) of pourable food products from sealed packs (3) having each a main portion (7) and opposite end portions (8, 9) arranged on opposite sides of main portion (7); each pack (3) comprising, for each end portion (8, 9), a fin (17, 18) and a pair of flaps (19, 20) projecting laterally from main portion (7); unit (1) comprises: a conveyor (60) which is fed with a plurality of packs (3) and which feeds the pack (3) along a forming path (B); and folding means (24) which interact with each pack (3) along forming path (B) to fold relative end fin (18) onto a relative end portion (8); conveyor (60) comprises at least a first and a second link (35a, 35b) articulated to each other; second link (35b) is arranged downstream of first link (35a), with reference to a first advancing direction of conveyor (60)along forming path (B); folding means (24) comprise: a slot (40) which is defined by first link (35a) and is adapted to receive said end fin (18); and a slide (72) operatively connected to second link (35b) and movable between a first position in which it at least partially engage slot (40), so as to fold said end fin (18) onto a relative said end portion (9), and a second position in which it is detached from slot (40).