Ten sesame varieties were evaluated using Randomized complete block design with three replications at Omo kuraz -1 sugar development project of South Omo, Southern Ethiopia, during 2018/19 under irrigated condition to estimate phenotypic and genotypic coefficients of variation, heritability and genetic advance for some important characters in sesame (Sesamum indicum L.). The treatment consisted of ten varieties of sesame namely: E, Tate, Kelafo- 74, Mehando-80, T-85, Adi, Abasena, S, Argene and Serkamo. Data were collected on phenological, growth, yield, yield components, oil content and oil yield and analyzed using SAS software version 9.0. The results showed that there were significant differences among the varieties for all characters studied. High estimates for GCV and PCV were observed in seed yield and oil yield, While Plant height to first branch, Plant height to first capsule, number of capsules per plant and harvest index showed moderate PCV and GCV and the remaining traits recorded low PCV and GCV. High estimates for heritability values were observed for traits Seed yield, Plant height to first branch, TSW, Plant height to first capsule, internode length and harvest index which indicated that for breeding activities and can be utilized in subsequent selections based on phenotypic expressions of individual plants for specific traits. And it further indicates the limited influence of the environment on the phenotypic expressions of the traits. Further computation for GAM indicated that high estimates were found for Seed yield, number of capsules per plant, Harvest index, Plant height to first branch, Plant height to first capsule which could further confirm the easy of selections based on phenotypic traits after cycle of selection using 5 % selection intensity. This study generally indicated that there were significance genetic variations among the varieties. Thus, there is enormous opportunity of using the germplasm in the improvement program for employing