Precision pathology of cancer is a new frontier—a systemic diagnostic approach to provide specific therapeutic targets and genetic and metabolic information for the treatment of patients. Not only are cancers extremely diverse, but there is also heterogenetic variation among patients with the same cancer; owing to differences in genetic makeup and metabolic levels, a drug may work in one patient but be toxic in another. This text covers both basic concepts (the role of the precision pathologist, ethical issues, molecular basis, tools used in precision pathology, and specimen procurement) and clinical practice (the precise genes/pathways, ongoing clinical trials, therapeutics, pharmacogenomics, pharmacoproteomics, and pharmacometabolomics) in precision pathology of cancer.