Seven specimens of Sciurus granatensis (red-tailed squirrel) rescued from illegal fauna traffic in Colombia were studied; they had different phenotypes according to colour. G, C, Q, R and NOR chromosome banding was used, being found a 2n=42 diploid number for the Sciurus granatensis Colombian squirrels. There were 3 karyomorphs according to fundamental number (FN) and different chromosomal characteristics caused by rearregement, suggesting that S. granatensis represents a complex of species. Relationships between karyotype and phenotype were not observed. The variation in the colour of sqirrels’ fur was probably due to environmental conditions. Key word: Sciurus, karyotype, red-tailed squirrel, Colombia, illegal traffic.