Mindfulness is widely used as a psychological intervention and its popularity is continuing to grow. The theory that underpins mindfulness interventions suggests the number of hours spent meditating is correlated with the development of mindfulness levels, which in turn, leads to correlated levels of psychological improvements. Meditation, however, is not the only method for developing mindfulness. Floatation-REST provides an environment with the potential for eliciting and developing mindfulness. The current study sought to investigate whether engaging in Mindfulness meditation in floatation-REST would increase levels of mindfulness beyond those developed in a normal sensory environment. Fifty participants were taught a Mindfulness-based meditation before dividing into a floatation-REST (experimental group) or group-meditation (control group). Participants meditated in their randomly selected conditions seven times for one-hour on a fortnightly basis, while also engaging in daily, 30-minute individual meditations. Mindfulness levels were measured before and after meditation training and then fortnightly throughout the duration of the study. As predicted, mindfulness levels showed significantly higher changes for those who meditated in floatation-REST, compared to those who solely meditated in a normal sensory environment. This result had a large effect size, eta squared = .07. Post-research analyses showed that both groups engaged in similar hours of individual meditation during the study. These results show that mindfulness meditation in floatation-REST has the capacity to raise mindfulness levels beyond dose-related amounts. These findings suggest floatation-REST is a tool which can be used in conjunction with Mindfulness training to enhance the development of mindfulness.