Volunteers are difficult to monitor because they are not liable to serious sanctions. We propose that we cannot learn about volunteer work from existing knowledge of paid employees. We then review the literature regarding volunteer commitment and performance. Based on a sample of 510 consistent volunteers in human service organizations, we assess three sets of variables (demographic, personality, and situational) to determine their significance in explaining variability in volunteer commitment and performance. The findings suggest that careful screening and use of symbolic rewards are significant in explaining variation in volunteer satisfaction, hours volunteered per month (commitment), and length of service (tenure).