The progressive reappearance of the Zika virus (ZIKV) infection since October 2013 and its circulation in >70 countries and territories (from French Polynesia to Brazil and other countries in the Americas, with sporadic spread in Europe and the East) has long been reported as a global public health emergency. ZIKV is a virus transmitted by arthropods (arboviruses), mainly by Aedes mosquitoes. ZIKV can also be transmitted to humans through mechanisms other than vector infection such as sexual intercourse, blood transfusions, mother-to-child transmission. The latter mode of transmission can give rise to a severe clinical form called Congenital Zika Syndrome (CZS) which can result in spontaneous abortion or serious pathological alterations in the fetus such as microcephaly, neurological and orofacial anomalies. In this study, beside a succinct overview of the etiological, microbiological, epidemiological aspects and modes of transmission of Zika virus infection, we have focused our attention on the pathogenetic and histopathological aspects in pregnancy and the pathogenetic and molecular mechanisms that can determine microcephaly, and consequently the clinical alterations, typical of the fetus and newborns, in a subject affected by CZS.