One of the fundamental goals of plant breeding is to evaluate genetic diversity in crop species, which aids in the development of breeding approaches. Therefore, this field experiment was conducted to assess mean performance, the genetic variability in garlic genotypes on bulb yield and related traits. The field evaluation of thirteen garlic genotypes and one released variety Holetta local (HL) was conducted at Kulumsa Agricultural Research Center using a randomized complete block design with three replications during the main growing seasons of 2020 and 2021. The analysis of variance indicated there were significant differences among the genotypes for all traits except days to physiological maturity in 2020 season, while only some growth and yield traits are significant in 2021 production season. Some of the genotypes GOG-065/18, GOG-057/18, GOG-047/18, GOG-064/18, GOG-068/18, GOG-045/18, and GOG-018/18 had mean performances higher than the standard check variety Holetta local (HL). Highest phenotypic (PCV) and genotypic (GCV) coefficients of variation recorded for total bulb yield tons per hectare and number of cloves per bulb, while the days to physiological maturity had the lowest heritability (h2b) in broad sense and genetic advance as a percent of mean (GAM), 67% and 33.89% (total bulb yield per hectare) and 1.13% to 0.08% (day to physiological maturity) respectively. High phenotypic and genotypic coefficients of variation coupled with high heritability and genetic advance as percent of mean were observed for total bulb yield tons per hectare number of cloves per bulb and clove weight. Therefore, selection for these characters would be effective for selecting genotypes for future garlic breeding programs.