Chamaedorea tepejilote Liebm is a specie of palm native to the south of Mexico and Central America. In Mexico, male inflorescences are consumed roasted, fried, boiled, or accompanied with other ingredients, due to a bitter aftertaste. Raw inflorescences have shown hypoglycemic, antitussive, and antimicrobial potentials, although the thermal treatment effect in these activities has not been thoroughly studied. Therefore, this study evaluated the impact of the three thermal treatments (hydrothermal (HP), steaming at elevated pressure (SEP), and microwave (MW)) on the nutritional and nutraceutical characteristics of Pacaya inflorescences. Inflorescences without thermal treatment (WTT) were considered as control. In nutritional characterization, protein content was the only fraction that increased significantly (p < 0.05) when applied to a thermal treatment. All thermal treatments modified significantly (p < 0.05) chlorophyll “a” content (HP reduced 0.59-fold; SEP and MW increased 0.07-0.25-fold), and chlorophyll “b” is reduced. There was a significant (p < 0.05) increase in all thermally treated samples in total carotenoids (between 0.80-fold and 8.73-fold) and total phenolic compounds (between 7.75-fold and 8.16-fold) compared with WTT. Microwave cooking was the only thermal treatment that significantly (p < 0.05) increased 0.97-fold the antioxidant activity in the DPPH radical. HP (14.11%) and SEP (18.20%) significantly (p < 0.05) reduced the dipeptidyl peptidase-IV enzyme inhibition concerning WTT (24.42%). These changes have been associated with partial loss, destruction, or denaturalization of cell walls’ proteins, lipids, or cellulose, causing liberating or creation of compounds with nutritional and nutraceutical activity.