In today's social context we strive for great competence and competitiveness in the business world which is also reflected in the educational context in which great emphasis is placed on school grades. Many parents put pressure on their children wanting them to excel in all areas, to enter college and, accordingly, wanting them to have the best possible grades. The function of grades is to represent certain knowledge with their numerical value. However, they cannot be completely reliable and of the reasons is that their measuring instruments are people, i.e. teachers who cannot be completely and exclusively objective. The aforementioned phenomenon is the starting point of this paper, which aims to determine students' attitudes towards teachers subjective grading in a negative way, when it comes to oral exams. Subjective grading in a negative way implies the student's experience of injustice, i.e. student interpretation of receiving a lower grade than the one he/she thinks he/she deserves and underestimation of their knowledge. The sample of the empirical research consists of 291 high school graduates from various parts of Croatia and examination is about their experience with the subjective grading during the period of secondary school education. By analyzing the data collected using an online survey, it was determined that almost every student encountered subjective grading at some point and that girls were more often subjectively graded compared to boys. The students consider the dominant factors of subjectivity to be factors that depend on the teacher, of which the most frequent factor is the personal equation, the second one is the halo effect, then the contrast error and the last one is the examination and grading technique. It has been shown that such subjectively-underestimating grades result in dissatisfaction, the decreasing in motivation for the subject and the changing in students perception of the subject teacher in a negative way.