Axonal growth and pathfinding is fundamental to the development and regeneration of the nervous system. Src tyrosine kinase has been implicated in this process; however, the detailed molecular and cellular mechanisms involving Src regulation of neuronal growth cone motility are not fully understood. We have focused on two potential roles of Src: (1) control of coupling between cell adhesion receptors and the underlying actin cytoskeleton and (2) regulation of actin dynamics and organization in lamellipodia and filopodia. Src2 and the Src substrate and actin binding protein cortactin accumulate at adhesion sites induced by the Aplysia cell adhesion molecule apCAM. Tension application increases Src2 activation state, while Src inhibition uncouples apCAM from actin flow. Expression of constitutively active (CA) Src2 increases density and lateral movements of filopodia in Aplysia growth cones, while the expression of dominant negative (DN) Src2 or cortactin phosphorylation mutants have opposite effects, suggesting a positive role of Src2 and cortactin in filopodia formation and integration within the lamellipodial actin network. On the other hand, analysis of filopodial actin dynamics suggests only a minor role for Src2 and cortactin in regulating actin assembly during filopodial extension. CA Src2- and cortactin-expressing growth cones have wider lamellipodia and spend more time in leading edge protrusion compared with control growth cones, suggesting that Src2 activity enhances actin assembly in growth cone lamellipodia. In summary, our results indicate that Src2/cortactin regulate lamellipodia protrusion and filopodia formation in neuronal growth cones as well as force transduction at apCAM adhesion sites.