<p>This randomized controlled trial investigated the effects of a spiritual care program on the sleep quality of 95 patients undergoing hemodialysis in Iran. Participants from Shahid Beheshti Hospital, Hamadan, were randomly assigned to either the experimental (<i>N</i> = 48) or control (<i>N</i> = 47) group. The intervention comprised six sessions (two sessions of 45–60&#xa0;min per week) and encompassed spiritual needs assessment, religious, psychological, supportive, and spiritual care, as well as evaluation. Sleep quality was measured using the Pittsburgh sleep quality index (PSQI), with scores &gt; 5 indicating poor sleep, at baseline, one month, and two months post-intervention. At the two-month follow-up, a significant between-group difference was observed in overall sleep quality and its dimensions (<i>P</i> &lt; 0.05). The experimental group demonstrated a significant improvement in sleep quality from baseline to two months post-intervention (<i>P</i> &lt; 0.001), whereas the control group exhibited a decline (<i>P</i> &lt; 0.05). These findings underscore the significance of incorporating spiritual care into nursing practice to enhance sleep quality in patients undergoing hemodialysis.</p><p>Trial registration: (Clinical trial registration code: IRCT20160110025929N41 and date: 11/11/2022).</p>