In Southeast Asia, schistosomiasis japonica is an important cause of hepatic fibrosis and gastrointestinal hemorrhage. Reliable methods to investigate portal hypertension (PHT) clinically and epidemiologically on community level are lacking. Doppler sonography is an established tool for investigating PHT in hospital settings. In Leyte, The Philippines, 137 individuals underwent color Doppler sonography, stool examination, and serology for hepatitis B and C, liver cell injury and cholestasis. A total of 85% of the study population had been infected with Schistosoma japonicum. Sonographically, periportal liver fibrosis was seen in 25% and reticular echogenicities (network pattern) in 44%. Portal blood flow was decreased or portosystemic collaterals were present in 10% (adults throughout) and correlated with periportal fibrosis, but not with network lesions. Chronic viral hepatitis was rare. Thus, hepatic lesions are frequent in adults but not in children in areas endemic for S. japonicum. Periportal liver fibrosis indicates a risk of PHT, and network pattern fibrosis apparently does not. Doppler sonography is suitable for research under tropical field conditions.