Mindfulness is known to aid well-being by lowering Rumination levels and raising self-regulation levels. Research into the area is expanding rapidly and interactions with personality, Rumination and well-being have already been found. However, the mediators and trends of these factors are not known. This investigation aimed to examine these changes throughout a Mindfulness intervention as well as comparing changes to a relaxation and control group. The study used 90 participants who completed the NEO-FFI and were divided into 3 groups (Mindfulness/ Relaxation/Control). Their Mindfulness and Rumination was tested throughout the intervention using self-reports, and life satisfaction was measured on the final day. The results were gathered and underwent correlational and repeated measures analyses. Personality was found to have a significant effect on both Mindfulness and Rumination, as expected however there was no difference found between the groups. This finding supports previous evidence regarding Mindfulness as a trait rather than a state and it was concluded that a longer investigation may highlight further interactions. Results, limitations and conclusions are discussed and further research, for example into age and gender proposed.