Individuals with prehypertension have a greater risk of developing hypertension and cardiovascular disease than those with normal blood pressure. Good cardiorespiratory fitness has been associated with a reduced risk for cardiovascular diseases, but whether it is related to slower progression of early atherosclerosis is unclear. We evaluated 442 women, aged 40-60 years, with resting systolic blood pressure 120-139 mmHg and diastolic blood pressure 80-89 mmHg, defined as prehypertension in cross-sectional study. Blood glucose, blood lipids and carotid intima-media thickness (CIMT) were measured at rest. Cardiorespiratory fitness (VO₂peak) was measured by respiratory gas exchange during a treadmill exercise test. Participants were divided into three cardiorespiratory fitness levels: low, moderate, and high. The prevalence of subclinical carotid atherosclerosis was defined as a mean carotid intima-media thickness greater than the 75^th percentile. After adjustment for various confounders, a high cardiorespiratory fitness level was associated with significantly lower SBP, DBP and CIMT compared with low and moderate fitness (p < 0.05). After adjustment for established risk factors, high and moderate fitness were each associated with significantly lower odds ratios for carotid atherosclerosis 0.74 (95% CI 0.45-0.92) and 0.70 (95% CI 0.46-0.95), respectively, compared with low fitness. Our results indicate that good cardiorespiratory fitness is associated with a slower progression of early atherosclerosis in middle-aged women. These findings are important, because they emphasize that middle-aged women can be evaluated for cardiorespiratory fitness to estimate their future risk for atherosclerotic vascular diseases.