Abstract: Seedlings of tomato (Lycopersicon esculentum Mill.) cv. 'Big Red' were used as scion and rootstock (self-grafted) and non-grafted control, while two hybrid tomatoes 'Heman' and 'Primavera' were used as rootstocks. Grafted and non-grafted plants were grown in the greenhouse and in the open-field. Grafted plants (BH and BP) were more vigorous than the non-grafted ones in the greenhouse as well as in the open-field. Plants grafted onto 'Heman' and 'Primavera' produced 32.5, 12.8% and 11.0 and 11.1% more fruit than the control (B) in the greenhouse and the open-field, respectively, whereas self-grafted plants BB had a lower yield in both cultivation conditions. However, the self-rooted plants B presented earliness in their performance, probably due to the lack of stress that followed the grafting operation. Quality and qualitative fruit characteristics were not affected by grafting.