Abstract: Background and Objective: Understanding the extent of genetic diversity among genotypes and organizing individuals into groups whose members are similar in some ways have an immense importance in plant breeding program. The objective of this study was to estimate the genetic diversity of 36 upland rice genotypes based on quantitative morphological traits. Materials and Methods: The field experiment was conducted using 6×6 simple lattice design in to two locations of southwestern Ethiopia (viz., Gojeb and Guraferda) during the 2016 main cropping season. Cluster analysis, distance analysis and principal component analysis were done using the SAS software version 9.3. Results: The analysis of variance over the two locations revealed significance differences (p<0.05) among genotypes for plant height, panicle length, culm length, filled grains per panicle, number of primary branches per panicle, days to maturity, days to heading, harvest index and grain yield. Cluster analysis indicated that 36 genotypes were grouped into 6 clusters and divergences between all pairs were significant (p<0.01). The inter-cluster distance was maximum between cluster five and six (D2 = 997) followed by cluster four and six (D2 = 811). The first six principal components (PCs) with eigenvalues greater than one explained 75.2% of the total variation among genotypes. The first and second PCs were responsible for about 19.3 and 14.5% of the total variation, respectively. In the first principal component character such as plant height (16.8%), panicle length (18.6) and culm length (18.3%) accounted high contribution effect of the total variation. Conclusion: This study confirmed the presence of variability among genotypes for most of the studied traits, which will create an opportunity for breeders to improve the yield of rice and other traits.