“As is your pathology so is your practice”, Nothing exemplifies this more than role of oncopathology in management of patients with cancer. Excellent quality pathology service provides maximum information to the clinician particularly when high-end sophisticated molecular techniques are unavailable. The oncopathologist has a dual role: diagnostic and theranostic. The diagnostic role includes not only labeling the disease, but also grading and staging whenever necessary. The theranostic role has evolved over the last two decades and includes the predictive and prognostic biomarker evaluation. The chapter tries to simplify this integral and intricate role of oncopathology through the journey of tissues.