This article examines the moderating effects of the Type A behaviour pattern on the relationship between paced work and psychological (mood) disturbance. The study was part of a broader survey investigation seeking to characterize job stress and health relationships among postal workers engaged in machine‐paced letter‐sorting operations. Data from 2803 paced letter sorters and 2715 non‐paced Postal Service employees were analysed in a behaviour pattern × pacing × sex (2 times 2 × 2) design. Paced work was found to have a significant effect on mood state. However, no evidence of a Type A moderating effect was found. Results of the study for males but not females were consistent with Sales' (1969) theory that the Type A person possesses personality traits that predispose self‐selection into stressful jobs. It was suggested that future studies of the relationships between pacing and the Type A pattern include multiple measures of the behaviour pred