Objective To assess the relationship between the preoperative plasma levels of hypothalamic corticotropin‑releasing factor‑1 (HCRT‑1) and melanin‑concentrating hormone (MCH) with postoperative sleep disorder (PSD) in eldery patients, and to evaluate their predictive value for PSD. Methods One hundred and eight elderly patients, American Society of Anesthesiologists (ASA) grade Ⅰ to Ⅲ, with no gender restrictions, who underwent elective hip or knee arthroplasty under spinal anesthesia at Chifeng Municipal Hospital from November 2021 to February 2023. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality 1 day before and 7 days after surgery. The patients were divided into two groups: a PSD group (n=69, PSQI score≥7 points) and a non‑PSD group (n=39, PSQI score<7 points). Preoperative day 1 plasma levels of HCRT‑1 and MCH, as well as postoperative day 7 plasma melatonin (MT) levels, were measured by enzyme‑linked immunosorbent assay (ELISA), and the HCRT‑1/MCH was calculated. All patients were equally divided into four groups (n=27) based on the ranking of preoperative day 1 plasma HCRT‑1 and MCH levels from low to high, and the trend tests were conducted to assess the trend of PSD incidence in each group. Spearman rank correlation analysis was performed to evaluate the relationship between preoperative day 1 plasma HCRT‑1, MCH levels and HCRT‑1/MCH, and postoperative day 7 PSQI scores. Pearson correlation analysis was used to assess the relationship between preoperative day 1 plasma HCRT‑1, MCH levels and HCRT‑1/MCH, and postoperative day 7 MT levels. Receiver operating characteristic curve (ROC curve) were plotted to evaluate the predictive value of preoperative day 1 plasma HCRT‑1, MCH, HCRT‑1/MCH, and combined HCRT‑1 and MCH for PSD. Multivariate logistic regression analysis was used to assess the relationship between preoperative day 1 plasma HCRT‑1 and MCH levels, and PSD. Results PSD occurred in 69 patients, with an incidence of 63.9%. Compared with the non‑PSD group, the PSD group showed increases in the preoperative day 1 plasma levels of HCRT‑1 and HCRT‑1/MCH (all P<0.05), and decreases in the preoperative day 1 plasma MCH levels and postoperative plasma MT levels on day 7 (all P<0.05). Trend analysis indicated that increased preoperative day 1 plasma HCRT‑1 levels (P<0.001) and decreased preoperative day 1 plasma MCH levels (P=0.003) were associated with a higher incidence of PSD. Spearman rank correlation analysis demonstrated that preoperative day 1 plasma HCRT‑1 levels and HCRT‑1/MCH were positively correlated with postoperative day 7 PSQI scores (r=0.52, P<0.001; r=0.62, P<0.001), while preoperative day 1 plasma MCH levels were negatively correlated with postoperative day 7 PSQI scores (r=−0.45, P<0.001). Pearson correlation analysis showed that preoperative day 1 plasma HCRT‑1 level and HCRT‑1/MCH were negatively correlated with postoperative day 7 MT levels (r=−0.56, P<0.001; r=−0.70, P<0.001), while preoperative day 1 plasma MCH levels were positively correlated with postoperative MT levels (r=0.57, P<0.001). ROC curve analysis indicated that preoperative day 1 plasma HCRT‑1, MCH, HCRT‑1/MCH, and the combination of HCRT‑1 and MCH could predict the occurrence of PSD, with area under the ROC curve(AUC) of 0.771, 0.713, 0.818, 0.817, respectively. Multivariate logistic regression analysis demonstrated that after adjusting for confounding factors, higher preoperative day 1 plasma HCRT‑1 levels [odds ratio (OR) 0.836 (95% confidence interval (CI) 0.769, 0.909), P<0.001] and lower preoperative day 1 plasma MCH levels [OR 1.085 (95%CI 1.026, 1.148), P=0.004] were independent risk factors for PSD in elderly patients. Conclusions Increased preoperative plasma HCRT‑1 levels and decreased MCH levels are independent risk factors for PSD in elderly patients and have good predictive value, with the HCRT‑1/MCH offering the highest predictive value for PSD.