Anatomical (or anatomic) pathology is the branch of medicine that involves the study of body organs and tissues(groups of cells). Anatomical pathology is considered one of the diagnostic branches of medicine, along with radiology and other pathology specialties (e.g. microbiology and chemical pathology). Its roles include determining the cause of certain diseases and the effect(s) that they are having on the body, assisting with the choice of treatment that will be given, aiding in giving a prognosis and determining what may have caused a person’s death.

Anatomical pathology is vital in those parts of medicine where a specimen of tissue or a sample of tissue cells are taken from the patient and sent to the laboratory. In these situations anatomical pathology is the specialty that gives the definitive diagnosis and allows clinicians to give the most appropriate advice and treatment to their patients.

There are two main subdivisions within anatomical pathology. The first is histopathology, which involves the examination of sampled whole tissues under the microscope. This is often aided by the use of special staining techniques and other associated tests, as described later. The second subdivision is cytopathology (cytology), which is the examination of single cells. A common cytology test is the cervical smear.

Anatomical pathologists are also involved in performing post-mortem examinations (or autopsies), which is the examination of the body of a deceased person. An autopsy is usually performed after a person has died of an illness which could not, for whatever reason, be properly or fully diagnosed before death. This would have to be consented to by the next of kin of the deceased person. If the cause of death is suspicious or unknown (i.e. not known to have been related to illness), the autopsy will be performed by a forensic pathologist, a related but separate type of medical specialist. Consent from next of kin is not required for a medico legal/coronial autopsy.