The authors report on a technique of combining low temperature nanowire synthesis with self-assembly of block copolymers in order to obtain a controlled array of nanowires. An oriented mesoporous inorganic thin film with similar to 12 nm pores was used as a template for synthesizing and controlling an array of vertical germanium nanowires. The number density of the nanowires growing through the pores was found to increase with an increase in the growth temperature. A low growth temperature of 275 degrees C results in sparse nanowire growth while growth at 340 degrees C results in approximately 50% of the pores being filled with nanowires. The growth through the pores is increased to close to 100% by growing the nanowires at a higher temperature of 380 degrees C. Scanning electron micrographs confirm the presence of the nanowires conforming to the shape and dimensions of the pores. Transmission electron microscopy further reveals the microstructure of nanowires inside the pores to be polycrystalline. The technique of templated nanowire growth-is a promising method to obtain well ordered arrays of nanowires which would be useful in a broad number of studies and applications. (c) 2006 American Vacuum Society.