This inquiry investigates whether effective implementation of pedagogical actions closely associated with strong engagement and greater than expected learning gains in writing by typically developing students apply similarly to engagement and gains in writing by students with mild to moderate intellectual disabilities (ID). It was undertaken in response to low levels of engagement and achievement in writing by students with ID noted by other researchers. A mixed methods research design, involving a three-month planned and deliberate instructional writing intervention with eight senior secondary students with ID in a Swedish special needs school, was employed. Pedagogical actions, designed to assist students recognise the purposefulness of writing tasks, involve them in constructing tasks and setting goals for successful implementation, observe tasks being demonstrated, reflect on the successful (or otherwise) completion of tasks and learn about writing in differentiated contexts, were considered in relation to learner outputs. A close association between strategic operationalisation of these actions and substantial increases in engagement and gains in writing by students with ID (particularly in relation to productivity, complexity and grammatical fluency) is noted.