We aimed to compare the amniotic fluid interleukin (IL)-6 concentrations measured using the automated electrochemiluminescence immunoassay method and ELISA, and to establish an IL-6 concentration cut-off value for intra-amniotic inflammation (IAI) in preterm prelabor rupture of membrranes (PPROM), which can be used in the automated electrochemiluminescence immunoassay method.