Karyomorphological analyses of three male sterile lines of Pennisetum americanum, their maintainers, two inbreds and two hybrids, which are morphologically distinct showed variations in their karyotypes. The three male sterile lines 732 A, 834 A and 843 A revealed differences in karyomorphology. Comparison of karyotypes of male steriles with their 'maintainers broughtout differences between the two. The two inbreds (PT 1921 and PT 3095) showed contrasting karyotypes whereas the two hybrids (UCH 11 and ABH 66) derived from a common female parent showed minor differences. The above results were confirmed using karyograph analysis, which led to infer that morphological closeness (male steriles and maintainers) is accompanied by restricted karyotypic variations and recognisable morphological difference follows a marked karyotypic difference.