The research aimed to study the relationship between pathological self-criticism and suicidal tendencies of secondary school students. To achieve the aim of this research, the pathological self-criticism scale and the suicidal tendencies scale were applied (prepared by the researcher), and the psychometric research sample was (456) (male and female) secondary school students aged between (16-18) years old, with an average age of (84.17) and a standard deviation (0.99), and the clinical research sample consisted of two cases who obtained high scores on the two scales. To achieve the aim of the clinical research, the Interview Form (prepared by the researcher), Indirect Clinical Observation, the Sacks Test sentences complete test , and Thematic Apperception test (T.A.T) were applied. The results revealed that there is a statistically positive correlation at the level of significance (0.01) between pathological criticism and suicidal tendencies. There are no statistically significant differences between the mean scores of males and females on the satisfactory self-criticism scale, and there are no statistically significant differences between the mean scores of males and females on the two dimensions of suicidal ideation and suicidal perceptions, and there were no statistically significant differences between the mean scores of students of the scientific and literary departments on the self-criticism scale and suicidal tendencies scale. The results also confirmed that suicidal tendencies can be predicted through satisfactory self-criticism. The results of the qualitative study agreed with the results of the quantitative analysis in the presence of some symptoms of pathological self-criticism and suicidal tendencies.