This study explores the main and interaction effects of framing messages and cause-related marketing on backing intentions by manipulating frame types, frame valences, and cause-related marketing in the message narratives of crowdfunding projects. We conduct an online experiment for a crowdfunding campaign and analyze data using independent-samples t-test and ANOVA. This study's findings show that negative messages lead to higher backing intentions than positive ones regarding attribute and goal framing messages. Narratives with cause-related marketing in crowdfunding projects had a more significant effect on increasing backing intentions than those without cause-related marketing. Positive attribute framing messages combined with cause-related marketing had significantly higher backing intentions than messages without cause-related marketing; for negative attribute framing, there was no significant difference between with and without cause-related marketing. This study theoretically advances the literature on reward-based crowdfunding, which provides scholars with insight into the effects of the written narrative design of crowdfunding projects on backing intentions and extends to the applications of framing effect theory and cause-related marketing. Practically, this study provides project initiators and crowdfunding platform operators with new perspectives on proposal copywriting content design and project operation. •Crowdfunding with cause-related marketing affects the backing intentions.•Negative framing messages lead to higher backing intentions.•Attribute framing with cause-related marketing affects the backing intentions.•Goal framing with cause-related marketing does not affect the backing intentions.