Therapeutic endoscopy with isotonic saline-epinephrine (ISE) injection is a convenient and widely used procedure for hemostasis in upper gastrointestinal bleeding. We retrospectively evaluated 36 patients (from January 1996 to April 1999) who had been diagnosed with recent or active bleeding due to Mallory-Weiss tears in emergency endoscopic examination. The endoscopic hemostatic method with ISE injection was performed in 15 of 36 patients. The other 21 patients received conservative treatment with hemodynamic support. Patient's clinical data, laboratory data, transfusion requirements, endoscopic findings, and length of hospital stays were evaluated. Initial hemoglobin was significantly lower in the ISE group than the conservative treatment group (9.74 +/- 2.86 g/dL vs. 12.57 +/- 2.80 g/dL, respectively; p < 0.01). Mean transfusion requirements were significantly higher in the ISE group than the conservative treatment group (7.26 +/- 8.78 units vs. 2.85 +/- 6.21 units, respectively; p < 0.1). Patients in the ISE group were supposed to be having a more severe bleeding episode. Most patients achieved initial hemostasis in the ISE group and the conservative treatment group (93% and 95%, respectively). The rebleeding rate was also similar in both groups (1 in 15 in the ISE group and I in 21 in the conservative treatment group). There was no significant difference in length of hospital stay and rebleeding between these two groups (3.47 +/- 1.92 days vs. 2.47 +/- 1.47 days, respectively: p = 0.89). The endoscopic ISE injection is an inexpensive, simple, convenient therapeutic method and it can achieve initial hemostasis for active Mallory-Weiss tears.