Following injury, axons of the peripheral nervous system regenerate, but only a small fraction reinnervate their original targets. Instead, regenerating axons grow too slowly to reach their original targets before supporting Schwann cells degenerate, and/or axons grow in the wrong direction and innervate inappropriate targets. To decipher the cellular and molecular mechanisms that guide regenerating axons toward their original targets, we study target selective regeneration of spinal motor nerves in larval zebrafish. Each nerve is composed of a ventral and a dorsal branch that diverge at a stereotyped choice-point. We have recently shown that following laser mediated nerve transection, axons of the dorsal branch select their original trajectory with high fidelity (>70%; Issacman-Beck et al, Neuron, 2015). Moreover, we find that slit1a mRNA is upregulated in denervated Schwann cells distal to the lesion site, suggesting a role for slit/robo signaling in directing regenerating dorsal axons. To directly probe the in vivo role of slit/robo signaling, we examined mutants for the slit receptor robo2. While robo2 appears dispensable for motor nerve development, we find that regenerating dorsal axons in robo2 mutants frequently (45%) fail to regenerate towards their original targets, and instead extend along ectopic trajectories. Interestingly, we find that exotosin-like 3 (extl3) mutants display a similar phenotype with higher frequency (61%). Extl3 modifies heparan sulfate proteoglycans, which are known to stabilize slit/robo binding. Finally, we find that robo2 and extl3 function specifically in directing axons of the dorsal nerve branch – regenerating axons of the ventral nerve branch select their original targets with high fidelity in robo2 and extl3 mutants. Thus, extl3 and robo2 mediate pathway specific axon guidance during peripheral nerve regeneration. We will present ongoing work on how robo2 and extl3 promote target specific regeneration.