The organ weights in cases of sudden infant death syndrome (SIDS) and undetermined deaths in previously healthy infants do not correspond to “the normal range” of organ weights in international standard charts for infants currently in use in some institutions. The aim of our study was to ascertain the organ weights of infants dying suddenly and unexpectedly in England and for whom a cause of death was not found, therefore falling under the category of SIDS or undetermined. We collated the organs weights from 2 institutions covering between them the South East and North of England including London, Yorkshire, and Derbyshire. The cases from The Royal London Hospital were autopsied between 1997 and 2013, and the cases from Sheffield Children's Hospital were autopsied between 2006 and 2013. There were 188 babies who had been born at term (62 female and 126 male) and 26 ex-premature babies (15 female and 11 male). Organs of male babies were slightly heavier than those of female babies but as there was no significant differences male and female babies were considered together. Comparison with standard charts (from 1932 and 1962) and with more recent charts confirmed the discrepancy between the older charts commonly in use with more recent measurements, including ours. The main reason for these differences is that babies in the recent charts were previously healthy babies with no long term disease and improved in the health of the population.