The present study aimed to explore the association between haptoglobin protein and mRNA expression and psoriasis. A total of 138 patients with psoriasis that were undergoing therapy at Linyi People's Hospital (Linyi, China) between January 2011 and January 2015 were enrolled in the present study. The mRNA expression levels of haptoglobin were detected by in situ hybridization; immunohistochemistry was used to detect haptoglobin protein expression; and double‑labeling immunofluorescence was used to count Langerhans cells; western blotting was also conducted to determine protein expression. A receiver operating characteristic (ROC) curve was generated to assess the diagnostic value of haptoglobin for psoriasis. Compared with the normal and negative control (NC) groups, the mRNA expression levels of haptoglobin were markedly increased in the experimental group (P<0.05). Haptoglobin protein expression was also markedly increased in the experimental group compared with in the normal and NC groups (P<0.05). Conversely, there was no significant difference in haptoglobin expression between the NC group and the normal group (P>0.05). The critical value of haptoglobin mRNA in the diagnosis of psoriasis was 2.93, and sensitivity and specificity were 91.3 and 73.6%, respectively. The area under the ROC curve was 0.883 [95% confidence interval (CI)=0.837‑0.929]. The critical value of haptoglobin protein in the diagnosis of psoriasis was 0.995, and sensitivity and specificity were 76.1 and 99.9%, respectively. The area under the ROC curve was 0.926 (95% CI=0.837‑0.929). The present study demonstrated that the mRNA and protein expression levels of haptoglobin were increased in patients with psoriasis. Haptoglobin mRNA and protein expression were closely associated with the occurrence of psoriasis; therefore, haptoglobin may be considered a promising novel clinical indicator for the diagnosis of psoriasis.