The study analysed the change in the proportion of business management undergraduate programme graduates in Turkey who received honours (>2.99) over the past two decades. It also investigated the factors that contribute to grade inflation and the distribution of course grades. The research employed various statistical methods, including the random effects estimator, ANOVA, t-test, and ANCOVA, to examine the GPAs and 515,739 student grades from 12,579 courses taken by 46,416 graduates of business management undergraduate programmes at 40 universities between 2002 and 2022. According to our findings, the percentage of undergraduate business management students graduating with honours (>2.99) has increased from 11% in 2002 to 56% in 2022. The most significant increases occurred in 2021 and 2022, which coincided with the COVID-19 pandemic. Our research also revealed grade inflation, with a significant increase of 28% after controlling for variables that may affect graduation grades in Turkish undergraduate business management programmes. The factors that affect course grades include the student’s gender, grade level, language of instruction, instructor title, and course content. According to our findings, it can be concluded that the rapid expansion of undergraduate business management programmes in Turkey has resulted in a decline in qualifications. This, in turn, has led to a rise in grades.