Repeated measurements of resting blood pressure and heart rate were obtained at the worksite for a sample of 441 male municipal employees ranging widely in age (M = 41 yr.), job level, and education. As a result of unusually high diastolic values (M = 91), over-all uncontrolled hypertension rates were very high (33% of the men exceeding 160 systolic or 95 diastolic including those on medication). Higher rates were obtained for blue collar as opposed to white collar employees and for those plant workers in the Division of Water as opposed to Sewerage and Drainage. Net of age, weight, smoking, education, and anti-hypertensive medication use, higher systolic and diastolic mean values were obtained for supervisors who were primarily employed as foremen and clerical personnel. Inter-plant differences in blood pressure were also found for primarily blue collar Sewers and Drains employees, though whites' and blacks' values were nearly identical. Comparisons with national blood pressure data indicate significant effects for level of job and education which again disfavored supervisors and clerical employees and in addition men who had more education. Whites' and blacks' blood pressures deviated significantly from expected values, the differences favoring blacks. Social psychological mechanisms which may mediate these effects are discussed.