3p interstitial deletions have emerged in recent years as a new cause of neurodevelopmental delay and intellectual disability. Since the first report of this condition in 1979, 16 cases have been described in the literature, delineating it as a presumptive syndrome. Here, we add a novel case presenting severely delayed neurodevelopment and psychomotor development; facial dysmorphism (square facies, broad forehead, short palpebral fissures, epicanthic folds, broad nasal bridge, and low-set malformed ears); cerebral, cardiac, and genital malformations; hand and feet anomalies; sacral sinus; and hearing impairment. Genetic investigations revealed a del(3)(p12.3p14.1) of 12.5 Mb, including 31 ORFs, among which ROBO2, PDZRN3, MITF, and FOXP1 are known to act in neurodevelopment. The clinical features of our patient are compared with those previously reported in the literature, thus providing further support for the delineation of the 3p interstitial deletion syndrome.