This paper examines causes of neonatal death in two contrasting Scottish communities in the second half of the nineteenth century. Individual death certificates allow comparison of the causes as recorded by different doctors and by lay informants. The paper finds that doctors almost always offer a medical-sounding cause of death, but that causes offered by individual doctors varied according to the nature of their practice, developments in medical terminology, and individual preference. Lay people were much more likely to offer no cause at all, or to suggest a non-medical term. Large percentages of deaths in the not-known category can therefore indicate poor medical provision, and are more likely to be found in remote rural areas and may be accompanied by an under-registration of very early neonatal infant deaths and their corresponding births, and by 'disguise' of certain causes of death. The paper examines the unusual age pattern of neonatal deaths on Skye and concludes that, although there is no mention of neonatal tetanus in the death registers, there is a substantial probability that the disease was present on the island. Comparisons of cause-of-death statistics between places and over time should therefore be made with extreme caution.