The current study investigated whether a domain-specific intervention targeting maths and executive functions of primary school children with a Roma background would be effective in improving their scholastic performance and executive functioning. In total, 122 students attending Grade 4 of elementary school took part in the project. The study concerned a pretest-intervention-training experimental design with three conditions: the experimental condition, an active and a passive control group. The results suggested that both maths performance and executive functions improved over time, with no significant differences between the three conditions. An additional correlational analysis indicated that pretest performance was not related to posttest performance for the children in the experimental and active control group.