To compare between the outcomes of fetuses with apparently isolated macrocephaly and syndromic ones. To present the prenatal findings and postnatal diagnoses in children with syndromic macrocephaly. We reviewed the files of all patients with fetal macrocephaly defined as a HC > 2 SD. All the patients were contacted and their development was evaluated. Adequate data was available for 97 patients, in 82 fetuses the macrocephaly was considered isolated (group A), and in 15 fetuses associated anomalies were identified (group B). Macrocephaly was diagnosed earlier in group B patients (28.7 vs. 31.4 weeks, P = 0.028); the head circumference in group B patients was larger (Z-score 3.0 vs. 2.4, P < 0.001). Group B CNS associated findings, as demonstrated by US and MRI, included mild ventriculomegaly (7), malformations of cortical development (7), callosal abnormalities (6), overdeveloped sulcation (3), large CSP (3), large subarachnoid space (2), mega cisterna magna (2), large 3rd ventricle (2); and periventricular pseudocyst, open operculum , and vermian dysgenesis (1 each). Syndromic diagnosis was reach in utero in 5 fetuses and after birth in 2. In 8 patients associated malformations were confirmed after birth but a specific diagnosis was not reached. In group A one child was diagnosed as having infantile autism. When fetal macrocephaly is associated with other brain or systemic anomalies syndromic macrocephaly can be diagnosed in utero. Most fetuses with syndromic macrocephaly have a HC more than 2.5 SD above the mean.