Sentence production requires rapid syntax generation and word retrieval. We investigated how healthy ageing affects these processes. In Experiment 1, syntactic priming significantly facilitated sentence production speed for both young and older adults. In Experiment 2, participants produced sentences with initial coordinate or simple phrases (e.g., the owl and the car move above the harp/the owl moves above the car and the harp); on half the trials, the second picture (car) was previewed. Without preview, both age groups were slower to initiate sentences with larger coordinate phrases, suggesting a similar planning scope. Young adults displayed speed benefits of preview both within and outside the initial phrase; however, older adults only displayed speed preview benefits within the initial phrase, and preview outside the initial phrase significantly increased error rates. Thus, syntactic planning scope appears unaffected by age, but there is age-related decline in the integration of lexical items into syntactic structures.