During the last few years, Zika virus rapidly spread across Central and South America and in the last months has spread also across Southern States of USA. As the epidemic began in Brazil, an increase of microcephaly cases was registered, causing concern and inducing the World Health Organization to raise an alarm. Certainly, the Zika virus, as many other viruses, has the capacity to induce severe cerebral lesions in foetuses of women infected during the first months of pregnancy. Moreover, more than 80% of cases of craniostenosys that verisimilarly took place in Brazil from September 2015 up to now were registered in few states of North- Eastern Brazil, where peaks of this malformation were registered several years before the appearance of Zika virus. In addition, in none of the 60 Countries where Zika virus is epidemiologically active an increase of the incidence of microcephaly has been reported. This paper intends to analyse some doubts concerning the link between Zika virus and the epidemic of craniostenosys.