To assess the effectiveness and acceptability of twice versus once-only Artificial Sweeping of Membrane (ASM) among uncomplicated primigravidae at 40 weeks of gestation in a tertiary care hospital in Sri Lanka. Methods A randomized controlled trial was performed among 240 uncomplicated primigravidae with ≤5 Modified Bishop's Score (MBS) at 40 weeks of gestation at teaching hospital Kandy from August 2013 to May 2014. Following randomization both groups received ASM at 40 weeks of gestation and the intervention group received a repeat ASM after 48 hours (40 weeks +2 days). The MBS was reassessed at 40 weeks +5 days. Participants who did not have spontaneous onset of labor (SOL) at 40 weeks +5 days were managed according to the ward policy of cervical ripening and Induction of Labor (IOL). Perceived discomfort, acceptability of the method, neonatal, maternal and labour outcomes were assessed. Results More participants in the intervention group established SOL within 48 hours compared to the controls (61.6% vs. 45%, RR=1.37, 95% CI=1.1-1.7, NNT=6). However,