This study examines a channel, students' nuisance, to explain grade inflation. "Students' nuisance" is defined by "students' pestering the professors for better grades." This paper contains two parts: the game theoretic model and the empirical tests. The model shows that the potential threat of students' nuisance can induce the professors to inflate grades. Ceteris paribus, a student is more likely to study little and to pester the professor for a better grade if: (1) the professor is lenient; (2) the studying cost is high; (3) the reward from pestering is high; (4) the cost of pestering is low. My original survey data show that 70%+ of professors think that students' nuisance is "annoying" and "costly in terms of time, effort, and energy." Regression results indicate that the more the student values the grade, the higher the studying cost, and the more likely the student is to pester the professor. (Contains 2 figures and 8 tables.)