A shock-absorbing braking device (10) for sliding doors (88) or for wardrobe panels is combined with a carriage (12) provided with rollers (14) sliding in an extruded profile (16), with a bottom base provided with a longitudinally extending slot (18) from which a pin or bolt (20) protrudes suitable to connect said carriage (12) to the sliding door or panel (88). The device comprises a containment shell (24), formed of opposite and complementary elements (28), in which at least one helical spring (26) and a shock-absorbing piston (30) acting in conjunction with a shaped cam (56) are placed, provided with an appendage forming a traction hook (62) suitable to abut with an activator (78) extending in said extruded profile (16). The shaped cam (56) is provided on opposite sides with a pin (64), destined to slide along a mixtilinear cavity (66, 66′) extending longitudinally along the inner face of each of the elements (28) forming the containment shell (24).