With the purpose of carrying out a cytogenetic comparison of the mosquito Psorophora confinnis from two Colombian strains (Lorica, Córdoba, and Granada, Meta) a karyological characterization study was carried out. Brain tissues from late 4'Vnstar larvae were used to obtain mitotic chromosomes through the squash technique. The chromosomal measurements were made to the following chromosomal characteristics: short arm, long arm, arm ratio, total length, relative length. centromeric index and relative length of the chromosomes. The morphometric data were compared. and standardized patterns were applied in order to classify the chromosomes in the analyzed karyotypes. They registered highly significant differences in the chromosomal total lengih and also in the values of the short and long arms of the chromosomes in the metaphases of the two strains. The C and G banding patterns establisned the correct position of the centromere and associated heterochromatic regions as well as the number of barids in each chromosomal pair in the karyotypes from Lorica and Granada strains. The results of morphometric data and the banding phenotypes suggest that Ps. confinnis exists in Colombia as a species complex.