OBJECTIVES: We investigated mortality differences according to socioeconomic status (SES) for employed persons in 27 states during 1984-1997. METHODS: SES was determined for persons aged 35-64 years according to the üsual occupation" listed on their death certificates. We used US Census denominator data. RESULTS: For all-cause mortality, rate ratios from lowest to highest SES quartile for men and women were 2.02, 1.69, 1.25, and 1.00 and 1.29, 1.01, 1.07, and 1.00, respectively. Percentage of all deaths attributable to being in the lowest 3 SES quartiles was 27\%. Inverse SES gradients were strong for most major causes of death except breast cancer and colorectal cancer. Heart disease mortality for highest and lowest SES quartiles dropped 45\% and 25\%, respectively, between 1984 and 1997. CONCLUSIONS: Mortality differences by SES were sustained through the 1990s and are increasing for men.