Hot chile peppers are the main element that characterizes the Mexican cuisine and culture for at least the past 8 centuries. The components responsible for chile hot flavor, capsaicinoids, are synthesized through the shikimic acid pathway. Their degradation is thought to be aided by the action of peroxidases. This work describes the evolution of capsaicinoids during the development of the fruit in three varieties of hot chile widely used in Mexico: `Habanero', `Arbol', and `Piquin', and its relation with the activity of peroxidases in these fruits. Plants were seeded and transplanted in a greenhouse and fruit were harvested after 10, 20, 30, 40, 50, and 60 days from fruit set. At 60 days from fruit set fruit were completely red and senescent. Total capsaicinoids, capsaicin, and dihidrocapsaicin were detected and quantified using HPLC. The activity of peroxidases was followed using spectrophotometry. Capsaicinoids were higher in the fruit of `Habanero', followed by `Arbol', and then by `Piquin'. Capsaicin was higher than dihidrocapsaicin in the three varieties. Capsaicinoids, capsaicin, and dihidrocapsaicin increased continuously and reached a peak at 50 days after fruit set in the varieties `Habanero' and `Arbol' and after 40 days in `Piquin', and then started to decline. Peroxidases had a maximum activity at pH 6.0, ≈1.0 mM of capsaicin, and 1.0–1.5 mM of H2O2. The activity of peroxidases was slightly high after 10 days from fruit set, decreased, and started to increase again after 50 days from fruit set, which might be related to the evolution of the capsaicinoids.