Cytogenetic analysis of two sacral chordomas revealed two distinct abnormal clones in one of the cases: 44,XY,t(1;3)(q42;q11), -2,der(7)t(2;7)(q23;q32), -21 and 46,X,t(Y;8)(q12;q22), t(1;14)(p34;q32),t(5;10)(q13;p11). All cells analyzed from the second case were cytogenetically normal. To the best of our knowledge, chordomas have not previously been subjected to cytogenetic analysis.