The chromosome numbers of 54 Lebanese Rhopalocera are given. 11 of them represent species not previously studied, while 26 of the remainder are endemic subspecies (often very characteristic) of species studied elsewhere. The findings are compared to the existing body of knowledge. The karyology is found to be very stable over wide geographical areas and, therefore, chromosome counts are a useful taxonomical tool for many groups of Rhopalocera. The chromosome counts of species not previously studied generally fall within the expected range for the respective genera and families. A simplified technique for karyological studies through non-permanent squash preparations is outlined.