The authors studied 33,494 deaths occurring in Londrina, State of Paraná, Brazil, from 1936 to 1982. The deaths were divided into two groups: residents and invaders, who lived outside the Londrina municipal limits. Invaders were studied as to origin, place of occurrence, cause, and diagnostic confirmation and compared with residents across proportional mortality. An attempt was made to identify a relationship between invaders' deaths and Londrina's historical development, especially migratory phenomena and health care improvements. Results showed that over the course of the period studied, most of the outsiders who had died in Londrina (over 80%) were from northern Paraná. Identification of the proportion of in-hospital deaths, diagnostic confirmation, and criteria from several chapters of the International Classification of Diseases showed that outsiders had received proportionally more medical care. Londrina's medical care attracted outsiders from the beginning of the period onward, a trend that was further consolidated after 1970.