To investigate the prognostic value of serum inhibin A in patients with acute respiratory distress syndrome. Methods A total of 102 ARDS patients admitted to The Affiliated Hospital of Yan'an University from June 2017 to September 2020 were selected as the research objects. According to the prognosis of the patients. They were divided into death group (48 cases) and survival group (54 cases), and according to the severity of the disease, they were divided into mild group (22 cases), moderate group (42 cases) and severe group (38 cases). Enzyme linked immunosorbent assay (ELISA) was used to determine the levels of serum inhibit A and related inflammatory markers. The difference of serum inhibit A levels among each group was compared. The diagnostic value of each index in the death of ARDS was analyzed by ROC curve. The related factors of death of ARDS were discussed by multivariate logistic regression model. Results Compared with the survival group, the levels of WBC, ALB, AST and GGT increased in the death group of ARDS (P＜0.05)), but there was no significant difference in the levels of Hb, HCT, PLT, TBIL, DBIL, Glu, CA, Cr, CHOL, HDL-C, LDL-C and TG (P＞0.05). Compared with the survival group, the levels of IL-4, TNF-α, Hs-CRP and APACHE Ⅱ score in the death group increased, and the differences were statistically significant (P＜0.05). Compared with the survival group, the serum inhibit A level in the death group was higher (P＜0.05). Compared with mild ARDS group, the serum inhibit A level in moderate and severe ARDS groups was higher (P＜0.05), and with the severity of ARDS, the serum inhibit A level gradually increased (P＜0.05). Serum inhibit A was positively correlated with IL-4, WBC, ALB, TNF-α, Hs-CRP and APACHE Ⅱ score (P＜0.05). The AUC, sensitivity and specificity of serum inhibit A in the diagnosis of death in patients with acute respiratory distress syndrome were 0.898 (95%CI: 0.848-0.955), 85.4% and 85.2%, respectively, which were significantly higher than those of hs-CRP and APACHE Ⅱ score (P＜0.05). Multivariate logistic regression analysis showed that high level of inhibit A［ORand 95%CI: 4.595 (1.780-11.865)］, hs-CRP ［ORand 95%CI: 2.319 (1.497-3.589)］, APACHE II score ［OR and 95%CI:2.192 (1.367-3.516)］ were the risk factors of death in patients with acute respiratory distress syndrome (P＜0.05). Conclusion Serum inhibin A is positively correlated with the severity of acute respiratory distress syndrome. Serum inhibin A has high sensitivity and specificity in diagnosing the prognosis of acute respiratory distress syndrome. The increase of serum inhibin A is a prognostic risk factor for patients with acute respiratory distress syndrome.