The current study aimed at identifying Early Maladaptive Schemas EMSs that can predict obsessions and compulsions in a non-clinical sample of postgraduate students (N=150), ranging in age between (21- 40 years). The study also aimed at revealing the EMSs in two cases with high scores on obsessions and compulsions inventory through a clinical study using the Thematic Apperception Test T.A.T. Study measures included Young’s Schema Questionnaire (YSQ-S3), and the Padua inventory (PI) for obsessions and compulsions, as well as the Thematic Apperception Test T.A.T. Results revealed significant correlations between all early maladaptive schemas and students’ scores on PADUA inventory. Stepwise regression analysis showed that Vulnerability to harm or illness; Enmeshment/Undeveloped self; Abandonment and Emotional Inhibition schemas predicted the total score of obsessions and compulsions. Statistically significant differences in obsessions and compulsions were found between individuals with high and low scores on early maladaptive schemas. The results of the clinical study using T.A.T supported the findings of the psychometric study regarding the most prevalent and predicting maladaptive cognitive schemas among participants with high scores on obsessive compulsive disorder symptoms.