High-density arrays (5 x 10(6) cm(-1)) of parallel nanowires have been grown using the vicinal Pt(997) surface as a template. Single monatomic rows of Ag and Cu can be deposited with subrow precision. We demonstrate real-time monitoring and characterization of the growth of the atomic chains as a function of temperature by thermal energy helium atom scattering. Scanning tunneling microscopy provides further insight into the structure of the metal rows. Growth mode and alloying with the Pt substrate are discussed as a function of temperature. Our results provide the basis for the creation of surfaces with a uniform distribution of wires having the same average width for the investigation of the electronic, magnetic, and chemical properties of one-dimensional and quasi-one-dimensional metal structures.