The somatic karyotypes of five crocodilian species are described. These species include Caiman sclerops (spectacled caiman or South American alligator, 2N = 42), Alligator mississippiensis (North American alligator, 2N == 32), Crocoa¦ylus porosus (salt-water crocodile, 2N = 34), Crocodylus niloticus (Nile crocodile, 2N = 32), and Tomistoma schlegeli (false gavial, 2N = 32). Metacentric, submetacentric and telocentric chromosomes were observed in all species tested. Satellites were observed on a submetacentric element of A. mississippiensis, and the apparently identical chromosome with an obvious secondary constriction was found in both C. porosus and C. niloticus. No microchromosomes were found. Possible pathways of chromosomal evolution to explain the observed karyotypic relationships are suggested