<p>Humanity’s economic activities are believed to be crucial factors in the deterioration of the world’s natural environment, including biodiversity loss and climate change. While the pro-environmental behavior of donors or volunteers may contribute to environment conservation and reducing consumption, its relationship to life satisfaction is still inconclusive. This study, which used original web-based cross-sectional microdata collected from 37 countries on six continents based on an ordered logit model, was conducted to confirm the association between donation and volunteer activities for environment conservation on individuals’ level of life satisfaction. We find that donations and volunteer activities for environment conservation positively affect individuals’ level of life satisfaction. Compared to volunteer attendance, cash donation appears to have greater positive effects on the level of life satisfaction. Citizens who participated in the multiple dimensions of donation (goods or cash) and volunteer activities for natural environmental conservation had a higher likelihood of satisfaction in 27 out of 37 countries: Brazil, Chile, China, Colombia, France, Germany, Greece, India, Indonesia, Italy, Japan, Malaysia, Mexico, Mongolia, Philippines, Poland, Russia, Singapore, Spain, Sri Lanka, Sweden, Thailand, Turkey, United Kingdom, United States, Venezuela, and Vietnam. The positive relationship between household income and life satisfaction was confirmed in 33 out of 37 countries. When regulating policies, we recommend that the United Nations utilize international citizens’ altruistic behavior for environmental conservation to benefit this type of conservation.</p>