There is growing evidence that dyslexia may involve difficulty with implicit learning, which may hinder learners with dyslexia to acquire spelling skills in a foreign language through implicit instruction. Paradoxically, this is exactly how Dutch students with dyslexia learn English spelling at school. This research aims to determine if implementing explicit spelling instruction, based on a direct comparison between L1 Dutch and L2 English spelling, facilitates the development of spelling skills of dyslexic learners in English as a Foreign Language. The participants were 40 Dutch-speaking secondary-school students independently diagnosed with dyslexia (age 12-14). Twenty participants attended their regular English lessons (comparison group), whereas 20 other participants received explicit contrastive spelling instruction once a week for eight weeks (intervention group). The results reveal that during the eight weeks of the intervention spelling skills of the intervention group developed faster than those of the control group, and they remained at the same level five weeks after the intervention. These findings suggest that even a relatively short intervention based on explicit instruction of spelling rules and cross-linguistic comparisons has a facilitative effect on the development of spelling skills of students with dyslexia in a foreign language.