In an exploration of the effects of task-repetition practice on fluency development, English-as-a-foreign language learners performed three oral narrative tasks involving six-frame cartoons for 3 consecutive days. They engaged in task-repetition practice under either a blocked (Day 1: A-A-A; Day 2: B-B-B; Day 3: C-C-C) or an interleaved (Day 1: A-B-C; Day 2: A-B-C; Day 3: A-B-C) task repetition schedule. The results yielded by a posttest involving new six-frame cartoons indicated that blocked practice resulted in greater fluency development (faster articulation rate and shorter mid-clause pause duration) than did interleaved practice. Moreover, the learners in the blocked-practice group tended to pause more frequently at clause boundaries. Blocked practice also led to significantly longer mean length of run and higher phonation/time ratio during training, although this advantage failed to transfer to meaningful pretest-posttest changes. These dynamic fluency developmental patterns are discussed to elucidate the underlying proceduralization in L2 speech processes.