Summary Cowpea, Vigna unguiculata (L.) Walp., is an important crop for many developing countries. Its potential cannot be fully achieved due to scarse resistance to pathogens. Source of resistance are present in wild gene pool, therefore, the introduction of genes for valuable traits from wild species to Vigna unguiculata faced an obstacle due to crossability barriers between species. The study of the chromosomal morphology could be useful in a modern plant breeding approach of cowpea.Recently the use of image analysis system to the karyotyping of plant species with few chromosomes has allowed the production of detailed karyotypes employed for interspecific comparisons. Twelve species belonging to four different subgenera and to six sections according to Marechal et al. (1978) were analysed by image analysis system. The karyomorphological parameters were utilised for computing karyosimmetry according to Stebbins (1971).