Background Protracted labor is associated with an elevated risk of maternal and fetal complications. Results of randomized controlled trials on the efficacy in labor of phloroglucinol (PHL), a pure antispasmodic drug, are uncertain. Objectives To evaluate whether PHL is effective in shortening the first stage of labor. Search strategy MEDLINE, EMBASE, LILACS, Scopus, ClinicalTrials.gov, and the Cochrane Library were searched from inception to July 2020. Selection criteria Randomized controlled trials (RCTs) concerning women with a singleton vertex pregnancy at term who were treated with PHL. Data collection and analysis Relevant data were extracted and tabulated. Review Manager 5.3 was used for data analysis. Primary outcome evaluated was the mean reduction of the first stage of labor. Main results Five RCTs, including 487 pregnant women, were analyzed. The first stage of labor duration was significantly shorter in the treatment arm compared to the control group [MD−113.21 min (95% CI−119.63,–106.79)]. A significant shortening of the second stage was achieved in the PHL group [MD−11.12 min (95% CI−12.64,–9.75)] while no differences were reported for the third stage. Conclusions PHL might represent an effective treatment to shorten the duration of the first and second stage of labor. [ABSTRACT FROM AUTHOR]