The aim of the study was to evaluate The relation between morphology of lips and incisors and mandibular rotation in adult class Ι individuals and to explore the gender dimorphism for these measurments. Material and methods True lateral cephalometric radiograph of the sample that comprises 32 females and 30 males aged 18-25 years and they possess class I skeletally and dentally. The data were analyzed using independent sample t test and Pearson correlation analysis. Results: In males interlabial angle negatively correlated with U1-NS and positively with U1-L1 Nasolabial angle and mentolabial angle positively correlated with (NS-GoMe, FH-GoMe, B, Bijork angles) Zangle and ULT/ULH negatively correlated with (NS-GoMe, FH-GoMe, B, Bijork angles) in Females lower lip inclination positively correlated with (NS-GoMe, FH-GoMe, B, Bijork angles).