Students with intellectual disabilities need more time and explicit instruction to develop word decoding. Most previous research on interventions among these students is performed in English. Therefore, the current study examined the impact of a word-decoding intervention in Swedish on individual students with intellectual disabilities. A single-subject-design study was conducted with five students with mild intellectual disability in the fourth grade. They needed to enhance decoding, and Swedish was their first language. Their word and non-word decoding was measured during the baseline and intervention phases. The intervention with the Wolff Intensive Program was delivered by special education teachers supporting phonemic decoding and reading fluency training during 25 sessions. All five students developed their decoding as they decoded more words in a given time (NAP=0.84-1.00) and decreased their decoding errors in both word and nonword decoding (NAP=0.72-1.00). The results are promising but need to be confirmed in additional studies.