Cytogenetic analysis of a primary adrenocortical carcinoma revealed clonal rearrangements of several autosomes and sex chromosomes. In all metaphases the following marker chromosomes were present: 4p+,t(3;12)(p14;p13),14q+, t(15;20)(p11;q11), t(5;18) (p13.3;p11.2), psu dic(18)t(18.3)(p11.39;p12), and psu dic(20)t(20;9)(q11.2;p11). The results are discussed in relation to the cytogenetic findings in other solid tumors, especially of the kidney.