Objective To investigate the relationship and predictive value of blood urea nitrogen(BUN)levels with the risk of in-hospital mortality in patients with septic shock.Methods Clinical data of 328 patients diagnosed with septic shock from January 1,2018 to September 30,2023 in Shenzhen Second People's Hospital were retrospectively collected.The primary outcome indicator was in-hospital death in patients with septic shock.Simple logistic regression analyses was used to explore the correlation between BUN and in-hospital death in patients with septic shock;multiple logistic regression analyses model was used to explore the quantitative relationship between BUN and in-hospital death in septic shock,sensitivity analyses was utilized to test the stability of the results.Results Simple logistic regression analyses suggested that BUN was a risk factor for in-hospital mortality in patients with septic shock.Multiple logistic regression analyses showed a positive correlation between BUN and in-hospital mortality in patients with septic shock:the risk of in-hospital mortality in patients with septic shock was increased by 3.3%for every 1 mmol/L increase in BUN(OR=1.033,P<0.01);after adjusting for different vari-ables,the risk of in-hospital death increased by 2.9%(OR=1.029,P<0.05)and 3.2%(OR=1.032,P<0.05)for each 1 mmol/L increase in BUN,respectively.Sensitivity analyses further confirmed the stability of the results(OR=1.04,P<0.05).Conclusion There is a positive correlation between BUN levels and in-hospital death in patients with septic shock,and it has a predictive value for the risk of in-hospital death in patients with septic shock.