Background and Purpose. Determine the efficacy of indocyanine green (ICG) dye in enhancing near infrared (NIR) laser ablation of tumors in a mouse model. Methods. Mammary carcinoma cells of A/J mice were injected subcutaneously in the lower back of female A/J mice (n=6). Five to seven days post inoculation the tumors (7-9 mm) were treated with 755-nm laser using 70 J/cm2 radiant exposures and 3-ms pulse time. Epidermal cooling was accomplished by cryogen spray cooling. Two minutes prior to laser irradiation mice were injected, intravenously, with 4 mg/kg body weight of ICG solution. Results. Complete tumor ablation was observed in the tumor region and minor damage was seen in the healthy skin. No major skin damage was observed post treatment. Substantial damage (up to 100% coagulative necrosis) was observed in tissue collected from tumors that were treated with laser/ICG. Conclusions. Intravenous administration of 4 mg/kg ICG significantly enhanced thermal ablation of tumors during NIR laser irradiation while sparing healthy skin.