The objective of this research was to investigate the institutional and individual factors that influence scientists' data-sharing behaviors across different scientific disciplines. Two theoretical perspectives, institutional theory, and theory of planned behavior, were employed in developing a research model that showed the complementary nature of the institutional and individual factors influencing scientists' data-sharing behaviors. This research used a survey method to examine to what extent those institutional and individual factors influence scientists' data-sharing behaviors in a range of scientific disciplines. A national survey (with 1,317 scientists in 43 disciplines) showed that regulative pressure by journals, normative pressure at a discipline level, and perceived career benefit and scholarly altruism at an individual level had significant positive relationships with data-sharing behaviors, and that perceived effort had a significant negative relationship. Regulative pressure by funding agencies and the availability of data repositories at a discipline level and perceived career risk at an individual level were not found to have any significant relationships with data-sharing behaviors.