Based on a national representative sample of U.S. internet users, this article examines the impact of associational participation on the likelihood of making an online donation to a charity. The results indicated that internet users engaged in more offline groups and networks are more likely to donate online. Frequency of use of internet and social media do not influence general propensity to donate, thereby suggesting that online donations are a function of actual engagement in social groups, rather than of frequent exposure to the internet media. Individuals involved in choice-based groups were the most likely to donate online, compared to other types of organization participation and/or affiliation. The authors also find that general propensity to donate online (including charities respondents are unaffiliated with) and making monetary contributions specifically to the particular organizations individuals are active in have somewhat distinct determinants.