By using the Goldstone-boson equivalence theorem, the leading electroweak radiative corrections to the tree-level process t --> W+b are obtained in three different limits: (i) m(H) > m(t) > M(W), (ii) m(H) = m(t) > M(W), and (iii) m(t) > m(H) > M(W). Recently, several groups have done the same calculation without using the equivalence theorem approach and obtained slightly different results. We compare our results with these previous works.