Abstract: A connecting device for flexible pipes, including: a supporting body, having at least one tubular portion which may be inserted in a relative flexible pipe; a seal ring, positioned around the tubular portion of the supporting body and switchable between an engaging position wherein it retains the flexible pipe on the tubular portion and a releasing position wherein it disengages the flexible pipe; and a mechanism for moving the seal ring for switching the ring between the engaging position and the releasing position; the tubular portion of the supporting body also including at least one protruding element, extending from the outer surface of the tubular portion along the entire transversal extension of the portion; the protruding element being interposed between two adjacent zones of the tubular portion having different transversal cross-sectional dimensions.