In a series of 88 patients with acute cholangitis secondary to hepatolithiasis, 26 (30%) required emergency therapeutic intervention because of septicemic shock (n = 15), persistent fever (n = 8), or spreading peritonitis (n = 3). Analysis was made to define factors that predisposed to failure of conservative treatment and characteristics that could predict the need for emergency biliary decompression. The age, incidence of concomitant medical diseases, previous biliary surgery, positive blood culture, bacterial strains resistant to antibiotics used, and multiplicity of bacterial strains in bile cultures in patients who required emergency intervention were similar to these factors in patients who had elective operations after successful conservative management. The incidence of intrahepatic segmental obstruction by stones or strictures was similar, but many more patients who required emergency intervention had concomitant extrahepatic obstruction due to impacted common ductal stones or strictures. Logistic regression analysis of clinical, hematological, and biochemical data showed that maximum pulse rate within 24 hours of presentation (greater than 100 beats per minute, relative risk, 2.8) and platelet count at the time of admission (less than 150 x 10(9)/L, relative risk, 5.2) were the factors with independent significance in predicting the need for emergency therapeutic procedures. This finding may serve as a guideline for identifying high-risk patients for early intervention.