Objective: To compare laminaria and Dilapan-S for overnight cervical preparation before dilation and evacuation at 18-24 weeks’ gestation. Methods: This double-blind randomized trial compared laminaria with Dilapan-S for the primary outcome of dilation and evacuation operative time within two cohorts: 18-20 6/7 and 21-23 6/7 weeks’ gestation. We required 160 women to have 80% power to detect a 2-minute difference in operative time; to account for attrition/missing data estimation, we enrolled N=180. Secondary outcomes included initial cervical dilation, pain, ability to complete procedure on first attempt and complications. Results: We randomized 180 women evenly across treatment arms. We found no demographic differences between groups. Seven participants were not included in the analysis of the primary outcome variable due to missing data (laminaria=86, Dilapan-S=87). We found no difference in operative time in minutes by treatment group in either gestational cohort [early cohort (n=90): 5.90±3.06 laminaria, 6.31±4.45 Dilapan-S, p=.60; late cohort (n=83): 9.03±3.61 laminaria, 8.86±4.47 Dilapan-S, p=.78]. There was no difference in either gestational cohort with regard to initial dilation, procedure difficulty, and pain. Of the 24 procedures that could not be completed on first attempt, 75% were in the laminaria group; the difference between treatment groups for this outcome was significant in the early gestational cohort (8 laminara, 0 Dilapan-S; p=.01). There were four acute complications managed on site without hospital transfer (laminaria =1, Dilapan-S=3, p=.62). Conclusion: We found no difference in dilation and evacuation operative time when cervical preparation is achieved with overnight laminaria versus Dilapan-S, however Dilapan-S facilitated completion of dilation and evacuation on first attempt.