We examine whether donors value volunteer commitment disclosures reported on the IRS Form 990. Donors and volunteers prefer to make respective gifts of money and time to nonprofits that are effective in furthering their missions. Based on the premise that volunteers, as insiders to an organization, are better positioned than donors to judge the impact of their contributions, we hypothesize that volunteer commitment provides value relevant information to donors. We find that donations are positively associated with the level of volunteer commitment and that other (noisy) effectiveness disclosures – namely the program ratio and corporate governance disclosures – are more value relevant when considered alongside volunteer commitment. These results suggest that donors view volunteer commitment as a signal of effectiveness and useful in interpreting other measures of effectiveness. Our evidence is more pronounced among sophisticated donors and charitable (relative to medical and educational-oriented), more volunteer intensive, and more complex nonprofits.