The purpose of the study was to determine whether the application of a school intervention programme based on the theory of multiple intelligences improves the academic achievement of students with low intellectual capacity, and whether the intervention programme also improves their level of general intelligence. The assessment design is quasi-experimental, with a non-equivalent control group, and with pre- and post-treatment measurements. The independent variable is the administration of the programme and the dependent variables are participants' intellectual capacity and academic achievement in subject matters considered essential in the curriculum - mathematics, language and social sciences. The study was carried out with 113 students aged between 11 and 16 years. The results show that the project has fully achieved the proposed goals, contributed to scientific knowledge about the development of intelligence and show that the teaching of processes is one of the most effective methods to increase academic learning. Significant improvements were observed in learning and in intellectual capacity. (Contains 3 tables and 3 figures.)