This text examines selected writings produced by four leading Brazilian conservation scientists active in the 1920s, 1930s, and 1940s. Alberto José Sampaio (1881–1946), Armando Magalhães Corrêa (1889–1944), Cândido de Mello Leitão (1886–1948), and Frederico Carlos Hoehne (1882–1959) were prominent members of a “second generation” of Brazilian conservationists. Although they died on the average about sixty years ago, they have receded from memory and their publications have become all but inaccessible. We argue that their ideas, research, and institution-building efforts were highly pertinent and influential in their own time and remain valuable today as building blocks of Brazilian conservation awareness and policies. This article brings together biographical and professional data about each author and examines the texts that best illustrate their range of concerns, their sources, and their priorities in the field of nature conservation.