Introduction: This pilot study analyzes the effect of a cognitive training program in adults with intellectual disability (ID). Method: Twenty subjects (mean age 52.7 ± 9.77 years) with mild and moderate ID were divided in control and experimental group. Only the experimental group received the training program. This program was applied through the GNPT® (Guttmann, NeuroPersonalTrainer®) platform for people with ID. Results: The results revealed a significant improvement in the Kaufman Brief Intelligence Test-2 scores (Matrices subtest) in the experimental group [Z = 2.12; p = 0.03] after the intervention, indicating an enhancement in fluid ability due to effect of cognitive training program. Conclusion: Findings provide evidence of the importance of applying these programs in a systematized way in adults with ID.