The authors assessed the association between lipid responses to acute mental stress and fasting serum lipid levels 3 years later in 199 middle-aged men and women. Total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol increased following moderately stressful behavioral tasks. LDL cholesterol, HDL cholesterol, and total:HDL ratio measured 3 years later were predicted by acute stress responses independent of gender, age, socioeconomic position, change in body mass, smoking, alcohol consumption, or hormone replacement therapy baseline lipid levels. The odds of clinically elevated cholesterol were significantly greater in the highest compared with the lowest stress tertile, independent of baseline levels and covariates. Acute lipid stress responsivity may reflect processes that contribute to the development of elevated blood cholesterol concentration.