Between 2016 and 2017, we conducted structured interviews with herbalists in market stands in the providence of Trujillo, La Libertad, Peru in order to create a catalog of plants with anticarcinogenic properties. Herbalists shared information about species they use in cancer treatment, including common names, part of the plant used, methods of preparation, plant state, and frequency and method of administration as medicine. We combined this information with the Shannon-Wiener diversity and evenness index to complete a quantitative analysis of the anticarcinogenic species. Our results demonstrate that 46 different species representing 24 genera and 19 families are locally used in cancer treatment, with a Shannon-Wiener index of 3.6 and 0.9 respectively. Our catalog thus represents a great variety of species and source of potentially useful knowledge for fighting cancer.