Urinary Ethyl glucuronide (EtG) and Ethyl sulfate (EtS) are established markers of alcohol conumption. Measurement of these markers in serum offers certain advantages. This outpatient department based study evaluated performance of serum Ethyl glucuronide (EtG) and Ethyl sulphate (EtS) as biomarkers of recent alcohol consumption in alcohol dependent subjects. It also evaluated effect of alcohol dose and time since consumption on serum EtG and EtS concentration. Information regarding alcohol intake was collected using Time line follow back calendar method from 152 subjects. Blood samples were collected to determine serum EtG and EtS concentration. The results revealed that serum EtG (at a threshold of 45 ng/mL) could detect recent moderate to heavy alcohol consumption with 85 percent sensitivity and 89 percent specificity. The results also show that simultaneous measurement of EtS does not increase test accuracy. We found that dose of alcohol and time since alcohol consumption explain 68 and 62 percent variance in serum EtG and EtS levels. EtG testing in blood was found useful as a way to detect recent drinking. This sensitive and specific short-term biomarker provides valuable information about recent alcohol consumption.