Abstract: The present study is a meta-analysis of clinical studies evaluating the efficacy of Fresh Frozen Plasma (FFP) in the treatment of organophosphorus (OP) poisoning. PubMed, Scopus, Google Scholar and clinicaltials.gov were searched for studies investigating the effects of FFP in the treatment of OP poisoning. Mortality, intermediate syndrome (IMS) and hospital stay duration were the key outcomes of interest. Data were searched in the time period of 1966 through April 2014. Three studies that met our inclusion criteria were included in the analysis. Pooling of data showed that the Relative Risk (RR) of mortality in OP poisoning for three included trials comparing FFP to placebo was 0.77 (95% CI = 0.28 to 2.07 (P = 0.6)). The summary of RR for IMS in 2 studies was 0.74 with 95% CI = 0.05 to 10.99 (P = 0.83). The summary of a standard effect for the hospital stay duration in OP poisoning for two trials comparing FFP with placebo was -0.37 with 95% CI = -4.68 to 3.94. According to these data, FFP effect on OP poisoning in mortality, hospital stay duration and IMS incidence was not significant.