The number of sophisticated neurobiological techniques which can be applied on human brain has rapidly increased and causes an increased demand for post-mortem human brain tissue for research purposes. Brain banks, which collect post-mortem tissue from patients who suffered from neurological and psychiatric disorders, have become an important link between clinicians, scientists and neuropathologists involved in aging and dementia research. Due to the large variability of the material, there are many drawbacks in the use of post-mortem brains. Therefore, collecting human brain tissue for research should include matching for several factors, both ante-mortem and post-mortem. Some of the most important ante-mortem factors include age, sex, agonal state, seasonal alterations, circadian variation and clock time of death. The post-mortem factors which should be matched for include the post-mortem delay, fixation and storage time and lateralization. The material and data on aging and dementia, collected by the Netherlands Brain Bank in the past six years will serve in the present paper to illustrate the wide variety of potentialities and pitfalls in the use of post-mortem human brain tissue. Brain Bank organizations for various neurological diseases form at present an important clinico-pathological link in aging and dementia research and the availability of post-mortem human brain tissue makes it possible to investigate those diseases for which no animal model is available. In order to provide research groups with post-mortem brain tissue from Alzheimer's disease (AD) patients and controls, a brain bank was established by the end of 1985 in The Netherlands Institute for Brain Research. This brain bank is based upon research projects submitted in advance, specifying a variety of requirements such as: total number of brains needed, kind of fixation, agonal state, post-mortem delay, exact anatomical boundaries of the brain region, kind of fixation and other treatment requirements of the tissue. This Brain Bank has got two unique features: 1. Human brain tissue is obtained by means of rapid autopsies with a very short post-mortem delay, ranging between 2-4 hour. 2. Fresh brain dissection procedure is used, which is a difficult regime to establish, requiring qualified staff at inconvenient times. This dissection procedure is necessary for the immediate use of fresh tissue and advantageous in increasing the range of morphological, neurochemical, immunocytochemical, metabolic and other procedures which can be applied to tissues fixed in a different way or rapidly frozen brain tissue free of freezing artifacts.