An apparatus for survivor path decoding in a Viterbi decoder with a constraint length of K. The apparatus of the invention includes a best survivor unit, a a register-exchange network, and a trace-back unit. The best survivor unit receives path metrics of 2K−2 local winner states from which a best state is selected every L iterations. Meanwhile, the register-exchange network generates decision vectors of survivor paths leading to 2K−1 states at instant i according to decision bits of all states from instant i−L to instant i. Every L iterations the register-exchange network outputs L-bit decision vectors for all states at instant i. Then the trace-back unit stores the decision vectors and finds a global survivor path sequence by following the decision vectors back from the best state at instant i−L. In this manner, L decoded bits can be output from the trace-back unit every L iterations.