NCAM is an abundant cell adhesion molecule known to be important during development. Together with its posttranslational modification consisting of the addition of the polysaccharide polysialic acid (PSA), NCAM has been classically implicated in the regulation - among other developmental functions - of neurite outgrowth and stabilization of synaptic connections. A large body of work has also demonstrated that NCAM is required in the adult brain for different behavioral functions. In this review, we focus on those studies that have shown a role of NCAM and PSA-NCAM in the regulation of emotional responses and in the learning and memory processes