The present invention provides antibodies which bind to an epitope in the extracellular domain of human CC chemokine receptor 4 (CCR4) and which are capable of inhibiting the binding of macrophage-derived chemokine (MDC) and/or thymus and activation regulated chemokine (TARC) to CCR4. Also provided are inter alia immunoconjugates and compositions comprising such antibodies and methods and uses involving such antibodies, particularly in the medical and diagnostic fields.