Objective: To compare the diagnostic accuracy of placental alpha micro-globulin-1 assay with standard methods (Nitrazine stick test and clinical pooling of amniotic fluid in the posterior fornix) for detecting rupture of fetal membranes. Study Design: Prospective simple comparative diagnostic study. Setting: The study was conducted in Central Hospital,. Benin City, Nigeria between February 2015 to June 2015. Methods A three hundred and twenty patients at gestational age of 24 – 42 weeks with history, signs and symptoms suggestive of drainage of liquor were recruited after informed consent. Each patient was tested for rupture of fetal membranes using placental alpha microglobulin-1 immunoassay, Nitrazine stick and visual inspection of postenior fornix for liquour drainage to determine the accuracy of PAMG-1 compared with standard diagnostic tests. Individual patient had a pre-test questionnaire. The data generated were analysed using basic descriptive statistics. Main Outcome Measures-Placental alpha microglobulin -1 immunoassay and standard diagnostic methods (Nitrazine stick and pooling of liquour) method of rupture of fetal membranes.