A portable rivetting machine of the type including a channel (20) for slidingly receiving a series of interconnected rivet elements (rivets, U-shaped staples and the like), a resiliently-loaded slidable pusher for pushing the series of elements towards a discharge end. The channel (20) is internally provided with more than one pair of longitudinal dividing walls (38, 40) extending up from its base wall so as to define pairs of interstices (50, 52) disposed symmetrically with respect to the centre line of the channel as well as a central interstice (54) extending along the centre line of the channel. Each pair of two interstices (50, 52) is arranged to receive the legs of a respective series of U-shaped staples (E i , E 2 ) of a width corresponding to the distance between the interstices themselves. The central interstice (52) is arranged to receive a series of rivets (E 3 ). The pusher (56) includes the same number of parallel blades (60, 66, 68) as the number of interstices with each blade being housed in an interstice itself. The blades are interconnected by a yoke (62, 68) above the upper edges of the dividing walls of the channel (20).