Many of the larger employers in this country and abroad have benefited from industrial-organizational (I/O) psychologists’ evidence-based practice. However, charitable and not-for-profit organizations have not always been aware of our services or able to afford them when cognizant of them. Volunteering professional services to charitable organizations provides an opportunity to extend these benefits. In addition, volunteers reap the intrinsic rewards of service, acquire opportunities to hone their skills, and learn from others, and pro bono work has the potential of informing our understanding of the science and practice of I/O psychology. This paper provides five case studies from five I/O psychologists who share their volunteer experiences in their own words. Each case study describes what the I/O psychologist did for the organization, how he or she became involved, and what he or she got out of the experience and learned. The paper offers ways SIOP and the SIOP Foundation might facilitate volunteer activities and concludes by inviting readers to share their own volunteer experiences and suggestions for encouraging volunteer work.