The aim of this study was to examine the role of verbal encouragement in the mathematics' test performance of high-school students considering their self-efficacy and self-esteem. To measure the students' performance, two tests were constructed: one with low and one with medium task difficulty. The test consisted of easier tasks was made for a basis of future verbal encouragement. After the initial fase of filling in the Rosenberg's self-esttem scale and the Self-efficacy questionnare for children (SEQ-C) and doing the low difficulty maths' test, subjects were divided into two groups in the second fase of the study. In the second fase of the study, the control group solved a test of medium difficulty tasks, while the experimental group was verbally encouraged by both the experimenter and school psychologist before doing the test. The effect of verbal encouragement on maths' task performance was found, but the main effect of self-efficacy and self-esteem were not found. Verbally encouraged students were better at the maths' test than students who were not encouraged unrelated to their self-efficacy or self-esteem.