Carnation ( Dianthus caryophyllus
) is a worldwide reputed cut-flower crop. The objective of the study was to estimate various genetic parameters like critical difference (CD), phenotypic and genotypic variance, phenotypic and genotypic coefficient of variation (PCV and GCV), broad sense heritability and genetic gain, etc. of Dianthus
genotypes in order to assess the magnitude of variability for various agro-metrical characters.The study revealed highly significant differences for all the studied characters, indicating the presence of substantial genetic variability. The phenotypic coefficient of variation(PCV) was higher than its corresponding genotypic counterpart (GCV) for all characters studied. The highest GCV and PCV were evident in total branches per plant; and their lowest values for total number of flowers per plant along with plant height taken at 50% flowering phase. Broad sense heritability ranged from 33.33 (days to seed germination) to 95.30 (plant height at 50% flowering) per cent. Flowers per plant showed low genetic gain; hence, heterosis breeding would be recommended. These characters may serve as effective selection parameter in breeding programme for crop improvement.