We investigated prosody in two Swedish boys with autism spectrum condition (ASC) and subjected them individually to a year-long segmental intervention which was analysed using a single-subject experimental design. Acoustic measures were taken for F0 levels, F0 range and duration. The data were evaluated for syllable structure, phrase length and accent 2. Results showed a decrease in augmented F0 levels and an increase in the proportion of utterances within intermediate F0 ranges. The boys developed prosodic patterns more similar to that of typically developing children. In addition, the use of the important Swedish accent 2 increased.