Abstract: The objective of the study: The study of Relationships among optimism-pessimism, basic religious beliefs and divorce tendency among divorce applicant clients. Methodology: The design of the study is as relationships. The data population includes all of divorce applicant clients either self-referent or referred on behalf to courts and counseling agencies of Sanandaj city, one of the provinces of Kurdistan in year of 2010. 480 clients were selected at random from among the data population. Using the tools of optimism, pessimism inventory of Tabatabay and Hosaini (2002), basic religious beliefs Questionnaire(Rajaee et al. 2008), divorce tendency Inventory of Rusbult, Johnson, & Morrow (1986), the scales of independent variables of optimism, pessimism, basic religious beliefs, and divorce tendency were measured within divorce applicant clients . Results: The results showed the persons with high scores on basic religious beliefs had low scores in pessimism and divorce tendency and had more scores in optimism. A significant negative correlation was found between the pessimism and divorce tendency with basic religious beliefs. Multiple regression analysis showed that basic religious beliefs predicted and explained marital problem and divorce tendency. The results were discussed based on cognitive theories.