Experience with a score based on eight signs of Down syndrome is described. The signs are: (1) abundant neck skin, (2) mouth corners turned downward, (3) general hypotonia (4) flat face, (5) dysplastic ear, (6) epicanthic eye-fold, (7) gap between first and second toes, (8) protruding tongue. Examination was done in the first week of life of the newborn to evaluate his score. About five minutes were spent to score a child. An infant with a score of 6, 7, or 8 (showing 6, 7, or 8 signs) is considered clinically proven Down syndrome. When an infant has a score of 0, 1, or 2, the diagnosis is disproved. No false positive or false negative were observed among approximately 19,000 liveobrn infants born in this hospital in a five-year period (1973--1977). All the thirty infants where the diagnosis was considered were karyotyped, twenty-six had regular trisomy 21, and four had a normal karyotype. Of the twenty-one initially suspected cases who were checked for the score, twenty had a score of 6--8 (all had a karyotype of trisomy 21), only one had a score of 0--2 (she had a normal karyotype), and eight had a score of 3--5. This last group is heterogenous as it included five affected infants and three children with a normal karyotype and is the only group where cytogenetic investigation is indicated for diagnostic purposes. It is suggested that this score should be used routinely for the clinical evaluation of every newborn where the possibility of a diagnosis of Down syndrome has been raised.