The aim of the study was to explore how the decoding ability of pupils with reading difficulties was influenced by an intervention in decoding. The study was conducted with two different methods, BrAvkod and Trugs, that have been developed to train pupils reading ability. The study is based on a quantitative method of quasi-experimental design that gave the opportunity to compare the results of two groups: one intervention group and one control group, with pupils from grade three. There were ten pupils in each group. The intervention was conducted for 6 weeks, 4 days a week along with pre- and post-tests. A qualitative approach was also chosen in form of a questionnaire interview, to find out how the pupils experienced working with the methods. The results showed positive effects of intensive exercise with BrAvkod and Trugs. Hence, all pupils in the intervention group increased the test results regarding there decoding ability. As to the pupils´ evaluations about how they experienced working with the two different methods, a positive attitude emerged. Although the methods differ widely, Bravkod and Trugs were valued equally good by the pupils. In conclusions pupils´ decoding ability benefits from intensive training that is varied and combines group and individual sessions.