Before the late eighteenth century English mortality patterns were characterized at the national level by high and volatile mortality, relatively high mortality risk at all ages, and small or negligible survival advantages to wealth. An additional feature was the presence of very marked spatial differentials in mortality, a pattern that remains little explored. The most lethal environments were large towns and marsh areas, and these areas experienced the greatest improvements after the mid-eighteenth century. In this paper I revisit Mary Dobson’s thesis regarding the contribution of malaria to mortality in marsh parishes. There is indeed compelling evidence for endemic malaria in northern Europe before the twentieth century. However my re-examination of burial patterns, anecdotal evidence and contemporary comment provides little support for the argument that malaria was a major driver of excess mortality in marshlands, or that drainage and land improvement contributed to the marked mortality improvements that occurred after the mid-eighteenth century. I discuss the implications of these findings for our understanding of the major changes in mortality patterns that occurred in north-western Europe in this period.