The purpose of this study was to investigate the role of psychological contracts as a mediator in the relationship between organizational cultures and affective commitment. Two culture dimensions from the competing values framework were chosen, adhocracy cultures and clan cultures. Questionnaires were used to gather information, with 105 organizations and 948 employees taking part in the study. Data were collected both from the employees and from representative of the organization, with different questionnaires for the two different levels. A multi-level analysis was utilized in analyzing the data. The analysis revealed three significant findings. (1) Adhocracy cultures have a significant relationship with relational psychological contracts, (2) relational psychological contracts have a significant relationship with affective commitment, and (3) relational psychological contracts mediate the relationship between adhocracy cultures and affective commitment. This suggests that certain cultures will have an effect on the employee s psychological contracts with the employers, and that these psychological contracts in turn will determine the level of affective commitment the employees will have towards the organization.