OBJECTIVE To investigate the rate and topological profile of minor physical anomalies (MPAs) (prenatal errors of morphogenesis) in a group of children with Autism Spectrum Disorder (ASD), in order to better set a temporal framing of embryological factors involved in the neurodevelopmental etiology. METHODS A new modified Waldrop scale and a mixed approach of computerized photogrammetry and classic anthroposcopy was used to detect the presence or absence of 41 MPAs in 24 children (mean age: 7 years; sex ratio: 22M:2F) with ASD and 24 healthy comparison subjects (mean age: 7 years; sex ratio: 19M:5F) selected with DSM IV and CARS. RESULTS We found that children with ASD presenting MPAs (n=23; 96%) had significantly higher rates of MPAs in four body areas (head, ears, mouth, hands); interestingly three of 41 MPAs best discriminated ASD groups from comparison subjects: abnormal head circumference, abnormal cephalic index, abnormal palate. Moreover, our results suggest that most MPAs occur predominantly after the first trimester of pregnancy. CONCLUSIONS These results support a prenatal neurodevelopmental model of the autism spectrum disorder.