Mindfulness Based Interventions (MBIs) at work are on the rise and the aim of this study is to asses’ differential effects of a traditional Mindfulness Stress Reduction Program (MBSR) program compared to a brief version of Mindfulness Strength Practice (MBSP). Fifty participants were distributed between tree conditions (MBSR, MBSPC and a Waiting List Control Group). Each group was evaluated before and after the intervention programs with a self-report questionnaire indicating their levels of Mindfulness, Perceived Stress, Subjective Wellbeing, Work Engagement and Performance. Follow up measures were collected one month after the end of both programs. Preliminary analysis with repeated measures GLM utilizing a 3x2 design indicated statistically significant differences between groups for facets of mindfulness [Acting with Awareness (F (2) = 4.91, p<0.005,η2=0.179) and Non-Reactivity(F (2) = 6.69, p<0.05,η2=0.229)], Perceived Stress(F (2) = 4.01, p<0.05,η2=0.151)], and dimensions of Subjective Wellbeing [Self-Acceptance (F (2) = 3.73, p<0.005,η2=0.142); Autonomy(F (2) = 9.67, p<0.001,η2=0.301) and Environmental Mastery (F (2) = 4.62, p<0.05,η2=0.171)]. Preliminary results indicate that the traditional MBSR program was more successful in boosting levels of different facets of mindfulness and specific dimensions of wellbeing like self-acceptance. The shortened MSBSP program was more effective in boosting levels of autonomy and environmental mastery.