Traditional Mexican cheese production has been increasing in recent years. Thus, the increase in cheese whey volume must be carefully dealt with. Because of its high BOD (27–60 g L⁻¹) and DOQ (50–102 g L⁻¹), cheese whey represents a potential pollutant to the environment. However, studies have demonstrated the bioactivity of whey proteins. Therefore, this research aimed to evaluate the angiotensin-I-converting enzyme (ACE)-inhibitory activity of Fresco, Asadero and Chihuahua cheese whey. Samples corresponded to 3 different traditional cheese-making times. The <1 and 3–1 kDa whey fractions were obtained by ultrafiltration. The ACE-inhibitory activity was evaluated by standardized RP-HPLC methodology. Results showed that all cheese whey fractions were able to inhibit ACE activity. The highest ACE-inhibitory activity (67.3 ± 2.0%) was found in the < 1 kDa Fresco cheese whey fraction, however it was not significant different (P > 0.01) from the Asadero cheese whey fraction (65.3 ± 3.6%). In contrast, the <1 kDa Chihuahua cheese whey fraction presented the lowest (P < 0.01) activity (29.3 ± 7.5%). The 3–1 kDa Asadero cheese whey fraction showed high (P < 0.01) ACE-inhibitory activity value (66.1 ± 3.6%). In conclusion, Asadero and Fresco cheese whey presented relevant ACE-inhibitory activity. Therefore, whey obtained from the manufacture of these traditional Mexican cheeses may have a potential to be used as functional ingredients.