Regeneration of frog sympathetic neurons (B-cells) was found to be accompanied by sprouting of neurites within the ganglion. Neurons whose axons had been crushed and allowed to regenerate exhibited sprouts that arose mainly from the axon hillock and initial segment of the axon. Sprouting was apparent by 5-7 days and reached maximal values by 14-21 days, but had decreased to control levels by 42-49 days after injury. In contrast, neurons whose axons were prevented from regenerating (by cut and proximal ligation of nerves) exhibited sprouts which did not retract by 42-49 days. These results suggest that successful regeneration to targets may dictate the recovery of normal B-cell morphology in bullfrog sympathetic ganglia.