Two experiments were conducted on hydroponic tomatoes to assess the effect of tomato rootstocks/grafting on Trialeurodes vaporariorum populations. In the 1st experiment, the rootstock cultivars Arnold, Buffon, Emperador and Maxifort were grown as nongrafted or grafted with the scion cultivar, Clarabella, while the scion Clarabella was grown as nongrafted or self-grafted. In the 2nd experiment, a new scion Estatio was introduced to check the response of different genotypes to grafting and their attractiveness to the pest. The scions Clarabella and Estatio were self-grafted or grafted onto the rootstock cultivars Arnold, Buffon, Emperador and Maxifort. A two-factorial experimental design with four replications was applied in both studies, and the tomatoes were artificially infested with T. vaporariorum. In the 1st experiment lower population densities of T. vaporariorum adult and large nymphs were recorded on four rootstock cultivars compared to the densities on Clarabella. The cultivar Clarabella was characterised by the lowest contents of glucose and fructose in phloem sap and the most attractive cultivar to T. vaporariorum. This suggests the infestation by T. vaporariorum could lead to a decrease in these carbohydrates in leaves. The lengths, widths and surface area of T. vaporariorum were lower on nongrafted Clarabella compared to ones developed on Clarabella grafted onto Buffon. In the 2nd experiment, the adult and nymphal pest populations were decreased by grafting on rootstocks, while the effect of the tested scions was generally not significant. In conclusion, the use of tomato rootstocks could constitute a valuable tool in an integrated pest management strategy against the greenhouse whitefly T. vaporariorum.