Brazil is the larger producer of fresh oranges contributing with 55% of the world´s production. The state of São Paulo-Brazil produces more than 70% of Brazilian´s national fresh oranges production. In spite of the importance of the orange activity to the economy of Brazil, more than 70% of the orange producers abandoned the activity in São Paulo between 1995 and 2014 due mainly to considerable reduction in their profits. Adopting irrigation can lead to an increase in the production factor yields and, consequently, to a reduction on the production costs per orange box, restoring the producers’ profitability. This paper aims to identify and analyze the factors that influence the adoption of irrigation systems in orange orchards in São Paulo-Brazil by using descriptive statistics, hypothesis testing and a probit model. We identified that the number of oranges varieties grown in the property, the percentage of the total agricultural income obtained with the orange activity, the number of management tools used in the production system, the risk preference of the producer with respect to the orange commercialization, the experience of the producer in the agricultural activity and the amount of money spent with technical assistance impacted significantly the irrigation adoption.