Abstract: Objective To investigate the relationship between serum thioredoxin (Trx) and thioredoxin reductase (TrxR) levels and early neurological deterioration (END) in patients with acute cerebral infarction. Methods A total of 156 patients with acute cerebral infarction who were admitted to Shenyang Fourth People's Hospital from January 1, 2020 to December 31, 2021 were enrolled as a research group. According to the presence of END, they were divided into two groups: an END group (n=68) and a non-END group (n=88). Meanwhile, 70 healthy volunteers who underwent physical examination in our hospital were selected as a control group. Their levels of serum Trx and TrxR were detected by enzyme-linked immunosorbent assay. Their clinical baseline data and serum Trx and TrxR levels were compared. The receiver operating characteristic curve (ROC) and area under the curve (AUC) was used to evaluate the application of Trx and TrxR in predicting END in patients with acute cerebral infarction. The related factors affecting END in patients with acute cerebral infarction were analyzed by multivariate Logistic regression analysis. Results The research group showed remarkable higher serum Trx levels (P<0.05), and lower serum TrxR levels (P<0.05) than the control group. The serum Trx and TrxR levels in the END group were lower than those in the non-END group (P<0.05). The results of the ROC curve showed that the AUC of Trx and TrxR for predicting END in patients with acute cerebral infarction were 0.802 and 0.830, respectively, with cut-off values of 12.30 μg/L and 1.95×10³U/L, a sensitivity of 80.63% and 79.21%, and a specificity of 85.66% and 89.85%, respectively. The AUC of the combined use of Trx and TrxR in predicting END in patients with acute cerebral infarction was 0.910, with a sensitivity of 90.88%, and a specificity of 82.31%. Multivariate Logistic regression analysis showed that serum Trx, TrxR levels and NHISS scores were the risk factors for END in patients with acute cerebral infarction (P<0.05). Conclusions Serum Trx levels increase and TrxR levels decrease in patients with acute cerebral infarction. Both serum Trx and TrxR levels decrease in patients with END, and are influencing factors of END in patients with acute cerebral infarction, which can be used as clinical indicators for predicting END in patients with acute cerebral infarction.