The period 1875–1925 was remarkable in the history of parasitology mainly for the elucidation of the life cycles of parasites causing important parasitic diseases and the incrimination of vectors in their transmission. These discoveries were made by a small number of scientists working in the tropics a number of whom were Scots. Sir Patrick Manson, the discoverer of the mosquito transmission of filarial worms, was instrumental in directly or indirectly encouraging other Scots including Douglas Argyll-Robertson, David Blacklock, David Bruce, David Cunningham, Robert Leiper, William Leishman, George Low, Muriel Robertson and Ronald Ross, who all made significant discoveries across a wide spectrum of tropical diseases. Among these, William Leishman, Robert Leiper and Muriel Robertson were all graduates of the University of Glasgow and their achievements in the fields of leishmaniasis, schistosomiasis, dracunculiasis and African sleeping sickness, together with subsequent developments in these fields, are the subjects of the ten papers in this Special Issue of Parasitology.