A rotor blade in a fiber-reinforced composite design for a tail rotor of a rotary wing aircraft (helicopter), with a blade section (5; 5′) having a blade skin (a, r) and a blade body (b . . . g, s, t), which blade section (5; 5′) forms an aerodynamically effective profile, with a blade tip (6) that faces away from the hub of a drive device of the rotor; and with a coupling section (9, 11; 9′, 11′) which faces towards the hub, with an attachment device (2) for a tension-torque-transmission element (3) and for a control tube (4) is improved in that the blade section (5; 5′) and the coupling section (9, 11; 9′, 11′) include spar tapes (a . . . g) that go all the way through and that are made of unidirectional fiber material.