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Forest to pasture conversion can lead to a decrease of precipitation induced by the decrease of evapotranspiration starting a positive feedback in the climate system. The accelerated deforestation rate suffered by Amazonian region is of global concern due to the importance of the Amazonia to the climate. Improve the understanding of the impact of deforestation in the hydrological cycle is of the highest importance. Nowadays, Amazonian landscape is no longer a homogeneous surface of pristine primary forest, but an heterogeneous irregular patches of pasture and agriculture plots of various sizes. Besides this, those patches were many times abandoned, creating opportunities for the regrowth of original vegetation (secondary forests). Impacts of fragmentation, and more specifically natural regrowth, on regional climate and hydrology are not well known. Previous studies pointed that the conversion of primary forest to pasture or agricultural crops affect the precipitation and runoff, and consequently evapotranspiration at micro scales, but this effect is not always detected at larger temporal and spatial scales. Few works suggested that the evaporative fraction of the secondary forest increases with the age of the forest in comparison with mature primary forests. Therefore, the objective of this study was to compare the evapotranspiration of one site of primary forest with one site of ~20 years old secondary forest in Central Amazonia, and to evaluate whether the secondary forest has a role on the resilience of the Amazon system compensating the effects of the deforestation on the water cycle. The latent heat flux of the secondary forest during the dry season was 29% higher than in the primary forest. During the wet season the secondary forest also presented 17% higher latent heat flux than in primary forest. The values of evapotranspiration were 4.28 mm day-1 for secondary forest against 3.32 mm day-1 for primary forest during the dry season, which represents a difference of around 1 mm day-1. During the wet season, the evapotranspiration for secondary forest was 3.99 mm day-1 against 3.42 mm.day-1 for primary forest, resulting in a difference of around 0.57 mm day-1. The evaporative fraction during the dry season in the secondary forest was around 0.80 and in the primary forest was 0.70. During the wet season this difference was lower, 0.89 for secondary forest and around 0.82 for primary forest. These results show that the difference on energy available for evapotranspiration is not the only cause of the higher evapotranspiration of the secondary forest in comparison with the primary forest in both dry and wet seasons. In conclusion, our study demonstrate that the secondary forest may play a relevant role in the Amazonia system, and confirm the urgent need of a better understanding of the role of this type of vegetation on a basin wide water and energy balance. Additionally, improvement of the representation of secondary vegetation on atmospheric models and in the analysis of soil-water-atmosphere interaction studies at regional and global scales.