<p>Objective While much attention is given to the fifth vital sign, the utility of the 4 classic vital signs (blood pressure, respiratory rate, body temperature, and heart rate) has been neglected. The aim of this study was to assess a possible association between vital signs and the Sequential Organ Failure Assessment (SOFA) score in patients with sepsis. Methods We performed a prospective, observational study of 206 patients with sepsis. Blood pressure, respiratory rate, body temperature, and heart rate were measured on arrival at the hospital. The SOFA score was also determined on the day of admission. Results Bivariate correlation analysis showed that all of the vital signs were correlated with the SOFA score. Multiple regression analysis indicated that decreased values of systolic blood pressure (multivariate regression coefficient [Coef] = -0.030, 95% confidence interval [CI] = -0.046 to -0.013) and diastolic blood pressure (Coef = -0.045, 95% CI = -0.070 to -0.019), increased respiratory rate (Coef = 0.176, 95% CI = 0.112 to 0.240), and increased shock index (Coef = 4.232, 95% CI = 2.401 to 6.062) significantly influenced the SOFA score. Conclusion Increased respiratory rate