The aim of this study was to investigate the anesthetic effect and risk of epinephrine for subcutaneous single injection digital block. Either 3.0 mL 1.0% Lidocaine or a 3.0 mL 1.0% Lidocaine with (1 : 100,000) epinephrine was injected into the subcutaneous space at the middle point of the palmar digital crease of the 18 middle fingers of 9 healthy volunteers. The SpO(2) of the fingers decreased to a maximum of 97. No subjects showed any symptoms of ischemic injury. The time to anesthesia for the fingers was significantly shorter (P < 0.05), and the duration of anesthesia was significantly longer (P < 0.01) for the fingers in the epinephrine group. In conclusion, a subcutaneous single injection digital blocks with 3.0 mL of 1.0% Lidocaine and (1 : 100,000) epinephrine were safe, reducing the time to the onset of anesthesia, while also markedly prolonging the anesthesia.