Atypical attention has been reported in individuals with ASD with studies pointing to an increase in ADHD-like symptomatology. Individuals with ASD may also present academic difficulties and it is possible that they face a double-barrier for academic attainment from both core ASD symptomatology and from attention atypicalities, which are directly linked to academic performance. This raises the possibility that academic difficulties in ASD may benefit from cognitive training targeting attention. To test this possibility, we used the CPAT intervention in a double-blind, active control with follow-up intervention study in Brazil. The CPAT is a computerised attention training program that was recently piloted with schoolchildren with ASD in the UK. 26 participants (8 to 14 years) with ASD in the São Paulo’s ASD Reference Unit were assigned to either the CPAT (n=14) or active control group (n=12), which were matched at baseline. Two 45-minutes intervention sessions per week were conducted over a 2-month period. School performance, attention, fluid intelligence and behavior were assessed before, immediately after and 3 months following the intervention. Significant group by time interactions show improvements in math, reading, writing and attention that were maintained at follow-up for the CPAT (but not the active control) group, while parents of children from both groups tended to report behavioural improvements. We conclude that attention training has the potential to reduce obstacles for academic attainment in ASD. Combined with the previous pilot study, the current results point to the generality of the approach, which leads to similar outcomes in different cultural and social contexts.