Recent research has revealed neuro-cognitive commonalities between decisions for self and for others. However, very few direct comparisons have been made between decisions for self and others in the context of economic decision-making under risk. In this study, we compared gambling decisions for self and others using a within- participants design. We manipulated the level of uncertainty involved in acquisition of seed money for gambling to explore its potential role in mediating risky decisions. The results revealed that participants were signi cantly more risk-averse when making decisions for others than for self, and this behavioral di erence was stronger when the seed money for gambling was obtained with certainty. Moreover, additional analysis using the Social Value Orientation scale (Van Lange, Otten, De Bruin, & Joireman, 1997) revealed that the “individualistic” participants made the self-other distinction more clearly than the “prosocial” participants, indicating that a participant’s social- value orientation plays a role when making risky decisions for others.