BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after eating crayfish were admitted to the Emergency Department of Beijing Chao-yang Hospital between June 2013 and August 2017. Clinical data was retrospectively analyzed. RESULTS: Alcohol consumption and exercise were found to be most commonly associated with the onset of rhabdomyolysis after consuming crayfi sh. Most patients were young adults and the symptoms mostly occurred within 24 hours of consumption of crayfi sh. Clinical symptoms included myalgia (100%), fatigue (87.5%), nausea (43.8%), dizziness (62.5%), chest distress (37.5%) and fever (18.8%). Also found after laboratory testing was elevations in the levels of creatine kinase (11,376±5,535 U/L), myoglobin (350±158 ng/mL), lactate dehydrogenase (6,539±3,180 U/L), alanine transaminase (174±71 U/L) and aspartate aminase (348±100 U/L). The incidence of renal dysfunction was low (6.25%), and all 16 patients had a good prognosis. CONCLUSION: Patients with Haff disease exhibited typical symptoms after consuming crayfish, and laboratory findings gave highly accurate diagnostic results. The development of rhabdomyolysis was considered to be associated with alcohol consumption and exercise, but further studies are needed to demonstrate its relationship with crayfi sh consumption. Compared with other causes of rhabdomyolysis, rhabdomyolysis after crayfi sh consumption has fewer complications and better prognosis.