The present study had two purposes: 1) to examine the relationship between tendency to experience obsessional intrusive thoughts and tendency to worry; 2) to replicate and extend earlier findings (Purdon and Clark, 1993, 1994) on appraisal and thought suppression strategies in the persistence and control of obsessional intrusive thoughts. A sample of 160 college students were administered the Revised Obsessional Intrusions Inventory (ROII), the Penn State Worry Questionnaire (PSWQ), the Beck Depression Inventory (BDI), and the White Bear Suppression Inventory (WBSI). The ROII total score had minimal association with worry, trait thought suppression, or depressive symptoms, thereby supporting the distinctiveness of obsessional intrusive thoughts. Hierarchical multiple regression analyses revealed that cognitive appraisal, especially worries that the intrusion might come true in real life, accounted for a significant amount of variance in thought frequency and controllability. Thought suppression strategies accounted for substantially less variance in both frequency and control of intrusive thoughts. The results are discussed in terms of their support for Rachman's (1993) and Salkovskis' (1985, 1989) theories regarding the role of personal responsibility in the persistence of obsession-like intrusive thoughts.