High purity 2-naphthylacetonitrile with fewer impurities can be used as a starting material or intermediate for synthesizing various pharmaceutical products, agricultural chemicals, and chemical products, and a production method thereof. A high purity 2-naphthylacetonitrile having an HPLC purity of 2-naphthylacetonitrile of not less than 95 area %, and containing naphthalene compounds represented by the formulas (a)-(j) at a content of a predetermined area % or below. A method for producing high purity 2-naphthylacetonitrile, may include: subjecting 2′-acetonaphthone to a Willgerodt reaction in the presence of an additive where necessary, and hydrolyzing the obtained amide compound to give 2-naphthylacetic acid; and reacting the 2-naphthylacetic acid obtained in the subjecting, a halogenating agent and sulfamide in the presence of a catalyst as necessary in an organic solvent to give 2-naphthylacetonitrile.