We hypothesize that thermal imaging can serve as a good alter- native to other classical physiological measurements to monitor the crop–water status, especially when this crop is subjected to deficit-irrigation strategies. To test this hypothesis, we undertook the following tasks: (i) an evaluation of the feasibility of ther- mal imaging in papaya crop to assess the physiological status for different deficit irrigation regimes; establishing the hypothetical relationships between Tleaf and the gs, E and An; in terms of study- ing wheter possible changes in Tleaf are linked to physiological changes on the basis of gas-exchange measurements; (ii) and the determination of whether Tleaf–air can be considered a feasible index to monitor the papaya physiological status as a prelimi- nary step to schedule irrigation when this crop is subjected to DI strategies.