A fly-fishing reel is provided for rewinding a fishing line on a spool, whose movement is limited, in at least one sense, by a braking mechanism. The fly-fishing reel includes a self-supporting structure and a spool. The self-supporting structure includes a central axis which bears on it the braking mechanism, which includes a first lateral containing ring, a brake ring concentrically arranged within an adjustment track or ring, and a second lateral containing ring. The brake ring is a split ring defining a guide slot along which a braking adjustment member is displaced. The braking adjustment member expands or contracts the brake ring. A blocking member is also concentrically mounted on the adjustment track or ring, which is in turn arranged without a relative sliding among them within the spool.