Objective To investigate the effectiveness of a decision aid intervention on decision making about urinary diversion in bladder cancer patients, and to enhance the level of shared decision-making. Methods Sixty patients with bladder cancer scheduled for radical cystectomy were allocated into two groups chronologically. The control group (n=30) who admitted between October 2021 and April 2022 were given usual perioperative nursing care and health education, while the observation group (n=30) who admitted from May to November 2022 received decision aid intervention additionally. The effect was assessed using the Decisional Conflict Scale, the Decision Self-Efficacy Scale, and the Preparation for Decision Making Scale. Results Twenty-nine patients in each group completed the study. The observation group had significantly lower decisional conflict, whereas significantly higher decision self-efficacy and preparation for decision making compared to the control group immediately after the intervention (all P<0.05). Conclusion The decision aid intervention on decision making about urinary diversion in patients with bladder cancer effectively ameliorates their decisional conflict, and enhances decision self-efficacy and preparation for decision making.