circRNAs are covalently closed RNA molecules recently re-discovered thanks to the advances in RNA-seq technology. They are produced by the canonical spliceosome in a non-canonical splicing process, named back-splicing. Heterogeneous in internal composition and highly stable, circRNAs regained the attention of neuronal biologists because of their enrichment in brain and neuronal compartments. Moreover, several pioneering studies revealed a fine orchestration of circRNA expression in crucial stages of neuronal development, such as synaptogenesis. The growing evidence of circRNA enrichment in synapses raises the intriguing question as to the yet unknown molecular mechanisms leading to this unique neuronal sub-compartmentalization. In addition, in which of the compartments composing the synapse – dendrites and axon – circRNAs preferentially localize, is still largely elusive. Here, I have focused specifically on the pre-synaptic compartment – the axon – during specific stages of neuronal development. The proper development of the axon is crucial to guarantee the correct synapse formation. Impairments in this process can lead to severe neurodevelopment diseases. I explored circRNA expression in the axonal compartment, shedding light on circRNA distribution in and trafficking to the neuronal distal compartment. To reach these goals, I used Xenopus laevis retinal ganglion cell (RGC) developing axons as a model. The results presented in this thesis highlight an abundant expression of circRNAs in the axonal compartment, where they are enriched compared to the somatic one. The enrichment in axons led me to deeper explore their preferential axonal sub localization, by investigating how they reach the neuronal distal compartment. circDDX17 was selected as reference model of axonal circRNAs. Its tracking within the axon revealed an heterogenous distribution and shape. circDDX17 trafficking along the axon displayed an anterograde preferential directionality and slow speed giving hints to uncover the molecular mechanisms of circRNA translocation to the axonal compartment. Bioinformatic analysis revealed that the RNA-RBP complex formation, the most common and described mechanism of axonal transport, could underlie circRNA intracellular translocation. Taken together, my data uncover the axonal circRNA population and characterize their localization in the neuronal distal compartment.