<p>A total of thirty-six Ethiopian mustard genotypes were assessed for their morphological characteristics to conduct a multivariate analysis and evaluate the extent of trait associations, utilizing a simple lattice design at Holetta <i>Agricultural</i> Research <i>Center</i> and Kulumsa <i>Agricultural</i> Research <i>Center</i> during the main cropping season of 2019/2020. Data collection focused on eight quantitative traits, which were analyzed through SAS software applications in accordance with established biometric methodologies. The association study indicated that seed yield (kg) exhibited positive and significant phenotypic and genotypic correlations with all traits, with the exception of plant height (cm). Among the traits, plot yield (g) demonstrated the most substantial positive phenotypic direct effect on seed yield (kg), whereas days to maturity (days) had the least positive phenotypic direct effect. At the genotypic level, oil yield (kg) showed the highest positive direct effect on seed yield (kg), while days to maturity (days) again exhibited the lowest positive direct effect. The first three principal components extracted accounted for a significant percentage of the total variation, and the genotypes were categorized into four clusters, indicating moderate divergence. Utilizing yield per plot (g), oil content (%), days to flowering (days), thousand seed weight (g), and days to maturity(days) as selection criteria is essential for broadening the genetic base of Brassica carinata germplasm in Ethiopia, which is crucial for an effective breeding program. To validate the findings, it is advisable to further investigate these materials using advanced breeding techniques. Given that the data was collected from a single season, it is recommended to replicate the experiment across multiple locations and seasons for confirmation.</p>