Retention of staff is, and will continue to be, a critical issue in the sustainability of most organisations. When we consider retention in terms of volunteers, the issue becomes increasingly more complex as the volunteer workforce itself becomes a source of competition as not-for-profit organisations vie for the same scarce resource - volunteers. Organisations which intend to attract and retain a solid cadre of reliable volunteer labour must ensure they look within themselves to ensure they manage these staff well. Leadership is among the key management skills an organisation must hone to do this, and to do it well. This research looks at the development of a unique leadership program using Self Determination Theory (SDT) to train leaders to develop volunteer work environments which meet the three basic psychological needs that all humans have. The training program is discussed and its value is assessed through an experimental empirical research design. The findings show that leadership development which is focused towards SDT has strong benefits towards the retention of volunteers.