A genetically modified M13 bacteriophage template was used to biomineralize ZnO. A peptide, EAHVMHKVAPRP , with a known affinity for ZnO was genetically displayed on each of five copies of the pIII protein located at one tip of the M13 virus. Site-directed assembly using this pIII peptide fusion was studied using a variety of precursor concentrations, incubation times, and phage concentrations. For comparision, free ZnO-binding peptides were also used to biomineralize ZnO. Isolated, polydisperse, spherical ZnO nanoparticles were formed at all mineralization conditions containing the ZnO-binding M13 bacteriophage, whereas free peptide mineralization resulted in smaller, more irregularly shaped particles which agglomerated at longer incubation times. These studies are preliminary experiments in the investigation of ZnO biomineralization on the various structural proteins of the M13 bacteriophage and cooperative effects which occur between neighboring peptides.