Background <p>Poor sleep quality is a common health concern with wide-ranging consequences. Manual diaphragm release, by improving diaphragmatic function and autonomic balance, may help enhance sleep quality. This pilot feasibility study aimed to explore the preliminary effects of diaphragm release on sleep quality in healthy individuals.</p> Methods <p>35 participants were included in the study. The Pittsburgh Sleep Quality Index (PSQI) and Fitbit smartband were utilized to evaluate individuals’ sleep quality. The diaphragm release technique was administered over three sessions, with two days of rest in between each session.</p> Results <p>Following the intervention, increases in sleep duration and sleep score were observed as per Fitbit measurements (<i>p</i> &lt; 0.05). Post-intervention, statistically significant changes were found in sleep latency, sleep duration, sleep disturbance subscales, and the total score of the PSQI (<i>p</i> &lt; 0.05).</p> Conclusions <p>As a preliminary investigation, this pilot study suggests that diaphragm release may be a feasible and safe intervention to enhance sleep quality. Further randomized controlled trials using gold-standard sleep assessments are needed to confirm these findings.</p> Clinicaltrials.Gov ID <p>NCT05762913 (Date: 10/03/2023).</p>