In the study of the influence of caffeinated substance on sleep inhibition and mental alertness among undergraduates, the researcher found that caffeinated coffee was statistically significant in inhibiting sleep and inducing mental alertness in normal (good sleeper) undergraduates in the department of political Science, Enugu state university of science and technology In the study of the influence of caffeinated substance on sleep inhibition and mental alertness among undergraduates, the researcher found that caffeinated coffee was statistically significant in inhibiting sleep and inducing mental alertness in normal (good sleeper) undergraduates in the department of political Science, Enugu state university of science and technology.