BACKGROUND: This study was conducted to analyze, compare, and assess the indications, incidences, and types of chromosomal abnormalities in the amniotic fluid, chorionic villus sampling (CVS), and abortus and to compare these with those previously reported. METHODS: The study subjects included 1,995 cases of amniocentesis and 169 cases of abortus, 20 cases of CVS, 21 cases of cord blood, and 2 cases of cardiac-puncture fluid in the last ten years (June 1999 to May 2009). RESULTS: Among the indications, the maternal serum and triple/quad markers testing positive emerged the highest (57.5%). Other factors those were found were an advanced maternal age (over35) (19.5%) and abnormal ultrasonography findings (8.2%). The frequency of chromosomal abnormality in the amniotic fluid was 4.5%, wherein the numerical abnormality was 3.1% and the structural abnormality was 1.4%. Among the numerical abnormalities, trisomy of chromosome 21 emerged the highest (1.4%). The frequency of the chromosomal abnormality of CVS and abortus was 39.1%, the numerical abnormality was 23.7%, and the order of frequency for trisomy was obtained chromosomes 16, 22, and 21. In the sex ratio of the normal chromosomes, it was 1.1%, but it resulted in 0.5% in CVS. CONCLUSIONS: The results of this chromosomal study on amniotic fluid, CVS, and abortus could serve as useful data regarding the prenatal genetic abnormalities of fetuses and for genetic consultation.