A total of 2741 high-risk pregnant mothers underwent invasive prenatal procedures, and in 94 of them (3·4%), fetal chromosomal or genetic anomalies were detected. In this study, we report on single pericentric inversions of chromosome 9 as well as translocations, which constituted 32% (30 of 94) and 16% (15 of 94) of all identified chromosomal or genetic abnormalities, respectively. In six fetuses of the 30 with an inversion of chromosome 9, ultrasound findings were abnormal and consisted of hydramnios, anhydramnios, hydroureter, hydronephrosis, encephalocele and prune belly syndrome, occurring singly or in combination. Among the 15 fetuses with chromosomal translocations, five had sonographic abnormalities. In conclusion, we found detailed ultrasound survey of fetuses with either translocations or inversions of chromosome 9 to be an additional source of useful information concerning fetal status that could be of value in genetic counselling of affected parents.