This paper analyzes the productivity of the naturalists Anastasio Alfaro and Henri Pittier in a period of 59 years, time in which the two authors published 316 articles in various Costa Rican sources. Several metrics methods were applied to these items, such as productivity and collaboration of the authors, Bradford's Law and average life. Furthermore, the keywords were analyzed in order to identify the areas in which both authors primarily published their works. We conclude that these two authors remained very active in their years of research. They are considered the major producers of Lotka productivity index and had very limited cooperation of other authors in their publications. Moreover, their contributions to the historical memory of Costa Rica, in the biological sciences are of great importance.
