We investigated whether near-ultraviolet light emitted from light-emitting diodes (LEDs) effects Helicobacter pylori viability and whether this new method can potentially apply to eradication therapy. Three H. pylori strains were used for near-ultraviolet (UV) LED irradiation experiments. Viability of isolates exposed to near-UV light was compared with controls by counting colony forming units. A time-dependent bactericidal effect of near-UV light was definitely observed. LED irradiation with near-UV light showed effective bactericidal activity against H. pylori strains. Eradication therapy with LED might provide a new avenue of treatment in patients refractory to eradication due to antibiotic resistance and/or adverse effects of antibiotics.