Sepsis is one of major causes of mortality in non-cardiac ICU patients. The screening of the patients for sepsis needs a careful evaluation of criteria and confirmation of infection. SIRS criteria for identification of patients with sepsis is not alone sufficient. Lactate has been shown to be a very important severity marker in sepsis cases and has been found to be more useful for predicting the outcome of sepsis than common severity scores such as the Age and Chronic Health Evaluation (APACHE) II score and the Sepsis related Organ Failure Assessment (SOFA) score. The levels of lactate are very high in sepsis patients and earlier studies have tried to correlate the lactate levels with the onset and mortality associated with sepsis. Though evidence exists that lactate can be used as diagnostic marker in critically ill patients all the studies have been done only in Western countries. The present study aims at correlation between lactate levels and sepsis in Indian patients. Our study found significantly higher mean lactate values among patients of sepsis than control group (3.13 ± 2.86 vs. 2.16 ± 1.86 respectively, p = 0.03). The proportion of subjects with high lactate clearance (> 10% clearance) were higher among survivors as compared to non-survivors, while those with low lactate clearance (< 10% clearance) were higher among non-survivors than survivors within 6 hours, and between 12 to 18 hours of admission. Survival analysis between subjects with high and low lactate clearance within 6 hours and between 12 to 18 hours of admission showed a significantly higher survival in the group with high lactate clearance. Thus, this study is one of the earliest ones which shows that lactate levels and clearance could be used as reliable marker for non-cardiac ICU patients with infection and sepsis onset in Indian scenario.