Development of nanoparticle agents for cancer therapeutics and diagnostics is steadily progressing and was the subject of the inaugural conference entitled, “Nano in Cancer,” held during January 12-15, 2011, in Miami, FL. The meeting program was developed by co-chairs David Piwnica-Worms (Washington University in St. Louis), Jan Schnitzer (Proteogenomics Research Institute for Systems Medicine, San Diego), and Karen Wooley (Texas A&M University). Topics discussed for nanoparticle platforms under development included: nanotechnologies for cancer diagnostics and imaging, overcoming in vivo barriers, therapeutic nanoparticles and clinical prospects, and safety issues for nanotechnologies. Two important concepts emerged from this meeting. The first was the urgent need for uniform standards and protocols for nanoparticle characterization in vitro and in vivo, and the second was the continued need for discovery of definitive targets for tumor-directed nanoparticles across various cancers.