Tomato is attacked by numerous insects that can cause loss of fruit and leaves and even the death of the plant. Plant herbivory by insect pests is considered the biggest cause of losses in tomato crops, representing between 20 and 30% of total production in developing countries. The tomato leafminer (Tuta absoluta) is among the most important predators frequently found in commercial tomato crops in South America, Europe, North Africa and the Middle East, where it has caused extensive economic damage. Here, we hypothesized that the expression of the toxin Cry10Aa coding gene, under control of the actin 2 promoter from Arabidopsis thaliana, could generate tolerance to T. absoluta in genetically modified tomato plants. Results have shown that transgenic lines segregated the transgenes in a Mendelian fashion. One line, named L10, which presented the highest toxin level in leaves (8.3 ng/mg of fresh tissue), presented a reduction of 49.9% in the emergence of adults. This suggested an effect on the life cycle of T. absoluta interacting with transgenic plants that correctly express the Cry10Aa toxin. In addition, a remarkable difference was observed in the effect of herbivory on the L10 event when compared to the non-transgenic plants. This demonstrated the potential of Cry10Aa protein expression to generate tomato plants tolerant to T. absoluta, possibly in combination with other genes. It may form the foundation for the generation of elite varieties resistant to tomato leafminer, a devastating insect pest for horticultural crops.