Automated blood pressure devices are available in a growing number of shopping malls, drug stores and workplaces. This study evaluates behavior changes that occurred in employees who used these devices to self-monitor blood pressure at work. A cohort design with a nonequivalent control group was used to study blue-collar hospital employees. Experimental participants (N = 91) had daily access to a Vita Stat automated blood pressure device while controls (N = 102) did not. Life-style scores included one point for each of five risk-reducing behaviors. Experimentals who self-monitored at least weekly showed significant increases in life-style scores. The proportion of this group practicing at least three of five of the recommended behaviors increased from 56% at baseline to 76% at the four-month and 88% at the 12-month follow-up (p less than .001). Scores for experimentals who self-monitored less than weekly and for controls remained unchanged during the same period. These results suggest that weekly blood pressure self-monitoring at work is associated with improvements in life-style behaviors related to smoking, exercise, sodium restriction, and dieting.