The present study is a waitlist-controlled investigation of the impact of a Mindfulness-Based Stress Reduction (MBSR) program on mindful attentiveness, rumination and blood pressure (BP) in women with cancer. Female post-treatment cancer patients were recruited from the MBSR program waitlist. Participants completed self-report measures of mindfulness and rumination and measured casual BP at home before and after the 8-week MBSR program or waiting period. MBSR group participants demonstrated higher levels of mindful attentiveness and decreased ruminative thinking following the intervention but no difference in BP, when compared to controls. In the MBSR group, decreases in rumination correlated with decreases in SBP and increases in mindful attention. When participants were assigned to "Higher BP" and "Lower BP" conditions based on mean BP values at week 1, "Higher BP" participants in the MBSR group (n=19) had lower SBP at week 8 relative to the control group (n=16). A MBSR program may be efficacious in increasing mindful attention and decreasing rumination in women with cancer. Randomized controlled trials are needed to evaluate an impact on clinically elevated BP.