Since its inception in 2001, the best possible selves (BPS) activity has been the focus of more than 30 studies which have shown it to be a viable intervention for increasing optimism, positive affect, health and well-being. It is timely to critically review the findings from the BPS literature and suggest directions for future research. The majority of BPS studies have used an experimental methodology and have administered the BPS activity to diverse groups including students, adults, depressive individuals and suicidal inpatients. The BPS intervention can be effective when administered in-person or on-line and repeating the activity appears to enhance efficacy. Suggestions for future research include: (a) investigation of mediator variables, (b) additional outcome variables such as hope and appreciation, (c) comparative studies regarding dosage to enhance effectiveness, (d) extension of the BPS into a best-possible-other activity, (e) diversity of delivery methods, and (f) thematic content analysis of BPS text. [ABSTRACT FROM AUTHOR]