Neuronal differentiation is a multistep process that shapes and re-shapes neurons by progressing through several typical stages, including axon outgrowth, dendritogenesis and synapse formation. To systematically profile protein expression during neuronal differentiation we have used cultured hippocampal neurons at different developmental stages in combination with triplex stable isotope dimethyl labeling technique coupled to high-resolution tandem mass spectrometry (LC-MS/MS). In total >1,500 proteins show more than two-fold expression changes during the different developmental steps, indicating extensive remodeling of the neuron proteome during differentiation. To demonstrate the strength of our resource, we focused on neural cell adhesion molecule 1 (NCAM1) as a regulator for dendritic outgrowth during neuronal development. The transmembrane isoform of NCAM1, NCAM180, is strongly upregulated during dendrite outgrowth, highly enriched in dendritic growth cones and interacts with a large variety of actin binding proteins. Inducing actin polymerization rescues the NCAM1 knockdown phenotype, suggesting that NCAM180 stimulates dendritic arbor development by promoting actin filament growth at the dendritic growth cone. Thus, our quantitative map of neuronal proteome dynamics will serve as a rich resource for further analyses of neurodevelopmental regulated processes.