Objective To investigate the relationship between activation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway and multiple organ dysfunction in rats with sepsis. Methods Using a sepsis model produced by cecal ligation and puncture (CLP), 98 male Wistar rats were randomly divided into normal control group (n=10), CLP group (n=40), AG490 (JAK2 inhibitor) treatment group (n=24) and rapamycin (RPM, STAT3 inhibitor) treatment group (n=24). At serial time points, the animals in each group were sacrificed, then tissue samples from the liver, lungs, kidneys and small intestine were harvested to detect STAT1/3 activity, pulmonary myeloperoxidase (MPO) and small intestinal diamine oxidase (DAO) activities. Meanwhile, organ function parameters including serum aspartate transaminase (AST) and blood urea nitrogen (BUN) contents were also measured. Results At 2 hours after CLP, STAT1 activities were found to be enhanced rapidly in the liver, lungs and small intestine, peaking at 6-24 hours, but their increase was delayed in the kidneys. Compared with STAT1, STAT3 activities were weaker and detected only in the liver and lungs, with no detectable STAT3 in the small intestine and kidneys. Pretreatment with either AG490 or RPM significantly lowered STAT1 activities in the liver, lungs and small intestine as well as STAT3 activities in the liver and lungs (P0.05). Conclusions These data suggest that abdominal infection can result in intensive activation of STAT1 and STAT3 in vital organs, and they play important roles in the pathogenesis of sepsis. Inhibition of JAK/STAT pathway can attenuate multiple organ dysfunction secondary to CLP-induced sepsis in rats.