Appropriate antimicrobial therapy poses one of the greatest challenges during the management of a septic patient in the intensive care unit (ICU). Acute renal failure (ARF) is a common complication of sepsis and often occurs as a component of multiple organ dysfunction syndrome. Continuous renal replacement therapy (CRRT) is increasingly used as an effective extracorporeal blood purification therapy in this critically ill patient population. Available data demonstrate that sepsis, ARF and different modalities of CRRT may have profound effects on the pharmacokinetics and pharmacodynamics of various antimicrobial agents used in the ICU. Guidelines for antimicrobial prescription which will fit the individual patient undergoing a particular method of treatment are still unavailable. Understanding the principles of drug removal by CRRT and pharmacokinetics of various agents can help to modify the drug dosage and dosing intervals for individualized therapy. Meanwhile, monitoring the drug serum concentration is still mandatory whenever clinically feasible.