In thin study, we reported cytogenetic results and chromosomal abnormality rate according to indications in amniocentesis, chorionic villus sampling (CVS), and fetal blood sampling. We analyzed 500 cases of amniotic fluid cells, CVS, and fetal blood using standard cytogenetic techniques for screening chromosome abnormalities in Institute of Reproductive Medicine and Population, Seoul National University from January to December in 2012. The most frequent indication of amniocytes was abnormal maternal serum maker (36.3%), followed by abnormal ultrasonographic findings (22.8) and advanced maternal age (22.6). Chromosomal abnormalities of amniotic fluid samples were detected in 23 cases (4.9%). Down syndrome (1.5%) was the most common abnormality. In 4 translocation cases, one case of balanced reciprocal translocation and 3 cases of Robertsonian translocation were inherited by parent. Chromosome abnormality of fetal blood was detected in 2 cases of 12 cases contained trisomy 13 and mosaicism. These data provide information about the probable risks and benefits for prenatal counseling of pregnant women with the high risk.