Rumination is a maladaptive coping style that has been found to be associated with several negative outcomes, including depression and anxiety. In particular, rumination has been found to be associated with deficits in inhibiting irrelevant information. This study examined the relationship of rumination to depression, anxiety, and stress and examined gender differences in these relationships. It also examined inhibitory deficits in rumination using a negative priming task with both short- and long-term components and evaluated the efficacy of a negative priming paradigm which utilised single presentations of stimuli that were not confounded by stimulus-response bindings. The results found that rumination was associated with higher levels of depression, anxiety, and stress, in line with the classification of rumination as maladaptive. It was also discovered that the predictors of rumination differed between males and females, with rumination being predicted by stress and depression for females and by anxiety for males, indicating possible gender differences in the explanation of rumination. The negative priming paradigm used in this study failed to produce any significant negative priming, and indeed produced significant positive priming meaning that no conclusions could be drawn from the data about inhibitory deficits and rumination. The results did however highlight the importance of the probe distractor in negative priming as it appears that a lack of competition between the probe distractor and the probe target may be a possible reason for the failure to observe negative priming.