The potential of high energy e⁺e^- collisions to detect an anomalous Wtb coupling is discussed. The anomalous Wtb coupling is implemented in the calculation of cross sections of four fermion reactions containing a single on-mass-shell top quark and numerical results for {e⁺ e^- \rightarrow t \bar {b} \mu ^- \bar {\nu }_\mu } are presented.

PACS numbers: 12.15.--y, 14.65.Ha