Flavonoids are compounds that have multiple functions in plant biochemistry, physiology and ecology, within which defense and protection against stress are described. For carnation flowers, flavonoids have been described as fundamental compounds in defense processes, mainly against Fusarium oxysporum sp. dianthi. This is a vascular pathogen that causes significant losses in the cultivation of this type of flower. In this work, the biosynthesis of flavonoids in carnation roots during the interaction with Fod was studied in detail, evaluating both the constitutive level and the effect of inoculation with the pathogen, also, the compounds present at the constitutive level and some biochemical and molecular parameters associated with its biosynthesis. Additionally, the effect of the application of a potential biotic inducer of resistance prior to inoculation that is obtained directly from the pathogen was evaluated. For this, two commercial varieties were used, which were subjected to an inoculation process and sampling at different hours post-inoculation, to subsequently obtain methanolic extracts and analyze the flavonoids present using HPLC/MS. For biochemical and molecular parameters, spectrophotometric methods and the RT-qPCR technique were used to evaluate the transcriptional levels of some of the enzymes involved. The results presented in this study confirmed the importance of flavonoid biosynthesis in disease resistance. At the same time, it was evidenced that the elicitation prior to the inoculation process stimulated this process in the susceptible variety, which allowed it to be prepared for the battle against the pathogen. The knowledge generated in this study complements the work developed in this model carnation-fusarium, and acredited the central role of flavonoids, especially flavanol-type glycosylates, in inducing resistance using elicitors of biotic origin.