One hundred and seventy-five participants, aged 18-67, comprised of 26% males and 74% females, participated in a between-groups experiment aiming to investigate the effects of mental time travel on levels of in-the-moment mindfulness. Four separate conditions required participants to remember or imagine 2 positive or negative emotional life events, after which in-the-moment mindfulness was measured. Analyses revealed no significant difference between conditions on mindfulness levels. There were significant differences found between conditions on perceived functionalities and characteristics of constructed events. A number of non-hypothesized effects were also found. The study supported previous findings on the functional qualities of mental time travel, and afforded the opportunity to explore factors including how effective mental time travel is at influencing certain mental states.