Background: The impact of endometrial cavity fluid (ECF) on assisted reproductive technology (ART) outcomes has not been evaluated in a meta-analysis. Objectives: To evaluate the impact of ECF on the outcome of ART cycles. Search strategy: PubMed, China Academic Journals Full-text Database, and China Doctoral/Masters Dissertations Full-text Databases were searched for reports published in any language before January 1, 2015, using relevant keywords. Selection criteria: Studies were included if they compared the outcome of ART in women with and without ECF. Data collection and analysis: Background information, participants' characteristics, and study outcomes were recorded. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method. Main results: Six studies evaluating 5928 ART cycles were included. The pregnancy rate was significantly lower in the group with ECF than in the group without ECF (OR 0.74, 95% CI 0.55-0.98; P = 0.03). The same association was observed if the analysis included only patients with hydrosalpinx (OR 0.36, 95% Cl 0.15-0.86; P = 0.02). Conclusions: The clinical pregnancy rate after ART is significantly lower among patients with ECF than among those without ECF. In addition, if ECF is found in patients with hydrosalpinx, ART cycles should be cancelled after oocyte retrieval. (C) 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.