Genomics and proteomics are newly developing fields and have evolved rapidly accelerating the rate of clinical cancer research.The potential applications of genomics and proteomics in the field of oncology, especially in cancer diagnosis, are virtually unlimited.Although there is a continuing progress in cancer therapy, early diagnosis of cancer undoubtedly remains the most important factor in improving long-term survival of cancer patients.The identification of tumor markers suitable for the early diagnosis of cancer holds great promise to improve the clinical outcome of patients.Emerging technologies in genomics and proteomics have enabled researchers to better understand the biology of cancer and to discover new biomarkers for cancer diagnosis, treatment response, and clinical outcome with higher sensitivity and specificity.Replacement of low throughput techniques such as Northern, Southern, and Western blotting, reverse-transcription polymerase chain reaction, in-situ hybridization, immunohistochemistry, and two dimensional gel electrophoresis with high throughput techniques such as DNA, RNA, protein, and tissue microanrays, and mass spectrometry has been the mainstay of recent achievements in cancer diagnosis.