The serum ascites albumin gradient (SAAG) is widely used to help determine the cause of ascites formation. A serum ascites albumin gradient of > or = 1.1 g/dL reliably distinguishes portal hypertension-related ascites from other causes. To date, there are no published data on the impact of portal decompression on this gradient. The recent development of transjugular intrahepatic portosystemic shunt (TIPS) allows for nonsurgical decompression of portal hypertension by radiologically creating a portosystemic shunt. This study examines the short-term impact of portal decompression on the serum ascites albumin gradient (SAAG) in patients with portal hypertension-related ascites undergoing transjugular intrahepatic portosystemic shunt. Portal pressure measurements were obtained before and after TIPS placement. Serum ascites albumin gradient was determined before and at 6 and 24 hours post-TIPS placement. Fifteen patients were enrolled in the study. The mean portosystemic gradient (PSG) before TIPS was 21.0 +/- 9.2 mmHg, whereas the post-TIPS mean PSG was reduced to 11.0 +/- 6.3 mmHg, consistent with portal decompression (p = 0.005). The mean pre-TIPS serum ascites albumin gradient was 1.9 +/- 0.5 g/dL and was reduced to 1.7 +/- 0.5 g/dL at 6 hours (p = 0.003) and 1.4 +/- 0.4 g/dL at 24 hours (p = 0.002) after TIPS placement. These findings further solidify the association between the SAAG and portal hypertension.