Root system architecture (RSA) is important for supplying water and nutrients for crop growth and production. In the present investigation an attempt has been made to study the genetic variability present in root system architecture of tomato genotypes at vegetative stages. Fifteen tomato genotypes were evaluated in CRD with three replications at AICRP on Vegetable Crops, OUAT, Bhubaneswar during the year 2020-21. Three seedlings per pot were grown and observations were recorded on thirteen RSA traits. Analysis of variance indicated presence of significant differences among the tested genotypes in respect of different RSA traits. Number of root crossings showed the highest GCV (59.35). Broad sense heritability was the highest (97.56 %) in case of volume of fine roots. The results of D2 analysis revealed 4 numbers of clusters. Results on principal component analysis revealed that PC1 and PC2 had 65.32 % and 26.33 % of contribution towards total variability.