The acute limb ischemia (ALI) in neonates is a rare phenomenon, but with serious consequences if undiagnosed or untreated. The purpose of this review is to briefly present the etiology of ALI and morphological findings in correlation with specific causes. Etiology can be classified into two main groups: prenatal (in utero compression, thrombosis and embolism) and postnatal (iatrogenic, thromboembolism and vascular malformations). The most common cause of ALI is catheter-related thrombosis (almost 90% of thrombosis cases are associated with catheter use), but other rare causes like vascular malformations should not be overlooked. Ultrasound represents a non-invasive, inexpensive and widely available imaging technique, which provides sufficient information to evaluate the situation and establish proper therapeutic strategies. Morphological tests do not represent the standard diagnostic procedure in ALI, but they can provide useful information. The findings depend on the etiology: intraluminal thrombi, vascular changes, placental pathological modifications. Every morphological result must be correlated with the clinical picture and imagistic findings. In conclusion, ALI in neonates is a rare condition, usually associated with catheter use in intensive care unit setting, with multiple risk factors and conditions that increase the risk of occurrence.