The karyotype of Isthmiophora melis (Trematoda:Echinostomatidae) is described. The chromosome number in the diploid cell is 2n = 20. The absolute (La) and relative (Lr) lengths of the chromosomes, as well as the centromere position (Ic), are determined. The differences in length between the adjacent chromosomes in the ordered series are not great, with the exception of chromosome 1 which occupies 20.58% of the genome length. This chromosome is metacentric, with lightly stained and elongated centromere region with Giemsa staining. Chromosome 7 is submetacentric. Chromosomes 2 to 6 are defined as telo-subtelocentric, while chromosomes 8 to 10 are subtelo-submetacentric. The fundamental number of arms in the I. melis karyotype is NF-22.