Polish brain-death criteria, similar to the original Harvard criteria, were published in 1984. In 1990, they were converted to brainstem death criteria, and were revised twice, in 1994 and in 1996. However, they could not be used in many complicated clinical situations such as intoxication, metabolic alterations, major facial injury, infratentorial lesions, and cervical spinal cord injury. The new Polish Transplant Act, passed by the Polish Parliament in 2005, recommends implementation of criteria for whole-brain death for brain-death diagnosis. In 2007, the Polish Ministry of Health Commission outlined new Polish brain-death criteria. Optional use of instrumental confirmatory tests was implemented in the new Polish national code of practice for the diagnosis of brain death in adults. In children up to age 2 years, instrumental tests are obligatory. Initially, there were problems in understanding the new, slightly more complicated classifications of primary and secondary brain injuries, infratentorial and supratentorial processes, modified apnea test. A broad commentary that addressed the most frequently asked questions was published in Anesthesiology and Intensive Therapy, the official journal of the Polish Society of Anaesthesiology and Intensive Therapy. This article dealt with most of the problems associated with implementation of the new criteria for diagnosis of brain death.