In this work, we demonstrate the synthesis of cadmium sulfide (CdS) nanoparticles in aqueous solution with MS2 bacteriophages as a biotemplate. Bionanofabrication methods offer unique opportunities for nanomaterials synthesis, where choice of biotemplate can influence the size, shape and function of the produced material. Synthesis reactions are carried out under mild aqueous conditions, and thus hazardous organic solvents, high temperature, and extreme pH can be avoided. The MS2 bacteriophage is a potential template system for bionanofabrication of nanoscale materials due to its size and inherent physical/chemical properties. MS2 capsid proteins can be genetically modified to incorporate functional groups and sequences. Also, genomic RNA in MS2 can be degraded or replaced with other oligonucleotide sequences and still form intact capsids. In this work, we use MS2 for bio-assisted synthesis of CdS nanoparticles and adjust the amount of RNA present in the template to assess biotemplate-nanomaterial property relationships. Produced nanoparticles were probed with several techniques including UV-Vis, photoluminescence and Hi-Res TEM. Optical techniques revealed that CdS nanoparticles with predicated fluorescent properties form in the presence of MS2 and remain stable in aqueous solutions. In fact, MS2-templated CdS nanoparticles were stable at room temperature for several weeks. Presence of RNA in the capsid interior was found to have major impact on the biotemplating process. Hi-Res TEM micrographs verified the presence of nanocrystals and their association with the biotemplate. Bionanofabrication using viral templates holds promise to enable an efficient, controlled and environmentally sustainable synthesis approach for a range of important nanomaterials. The work presented here represents an additional step forward towards those goals.