Objective To explore the expressions of NOD-like receptor thermal protein domain associated protein 3 （NLRP3）， cysteinyl aspartate specific proteinase-1 （caspase-1）， and interleukin-17 （IL-17） in the pathological tissues of granulomatous mastitis （GM）， and to analyze their clinical significance. Methods Between January 2021 and December 2025， pathological tissues were obtained from 60 patients diagnosed with granulomatous mastitis （GM） at Hunan Provincial People's Hospital， while normal breast tissues were collected from 60 patients with benign breast lesions at the same hospital. These samples were respectively designated as the GM group and the control group. The expression levels of NLRP3， caspase-1， and IL-17 in the two groups were detected by means of the immunohistochemical streptavidin-peroxidase （SP） method. Based on the detection results of the above three indicators， the samples were classified into a positive group and a negative group. The clinicopathological characteristics of the patients were recorded， and the differences between the positive and negative groups （NLRP3， caspase-1， IL-17） were compared using the χ² test. The differences in NLRP3， caspase-1， and IL-17 among GM patients at different disease activity stages were analyzed. A P-value less than 0.05 indicated that the difference was statistically significant. Results The positive expression rates of NLRP3， caspase-1， and IL-17 in the GM group were significantly higher compared to those in the control group （P < 0.05）. In different clinical stages of GM， the positive expression rates of NLRP3， caspase-1， and IL-17 in the abscess stage and the ulcerative stage were significantly higher than those in the lump stage （P < 0.05）. Additionally， the positive expression rates in the ulcerative stage were slightly higher than those in the abscess stage， yet there was no significant difference among different groups （P > 0.05）. The positive expression rates of NLRP3， caspase-1， and IL-17 in patients with a maximum tumor diameter of ≥ 5 cm were significantly higher than those in patients with a maximum tumor diameter of < 5 cm （P < 0.05）. Conclusions The expressions of NLRP3， caspase-1， and IL-17 are up-regulated in GM tissues. All three of these molecules are associated with the clinical staging of GM and lesion size. NLRP3， caspase-1， and IL-17 may be involved in the inflammation and progression of GM.