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Hepatocellular carcinoma (HCC) is a major malignant tumor type with a high incidence and mortality. Infection with hepatitis virus is a high‑risk factor. Previous studies have demonstrated that microRNA (miR)‑223 was downregulated in HCC tissues. NOD‑like receptor family, pyrin domain containing 3 (NLRP3)‑is a potential target of miR‑223 and has a vital role in hepatitis infection. The present study was performed to investigate the role of miR‑223 in the proliferation and apoptosis of HCC cells through regulating NLRP3. A dual luciferase reporter assay was performed to confirm the direct interaction between miR‑223‑3p and the 3' untranslated region of NLRP3 mRNA. Hep3B cells were then transfected with miR‑223 mimics and the proliferation and apoptosis were determined by an MTT and a flow cytometric assay, respectively. The expression of NLRP3 and caspase‑1 was analyzed at the mRNA as well as at the protein level by reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. The secretion of interleukin (IL)‑1β and IL‑18 in the culture supernatants was measured by ELISA. The dual luciferase assay confirmed NLRP3 as a direct target of miR‑223. Overexpression of miR‑223 in hep3B cells significantly suppressed cell proliferation and promoted apoptosis. Furthermore, the expression of NLRP3 was downregulated by miR‑223 transfection. Certain downstream factors of the NLRP3 pathway were also downregulated following overexpression of miR‑223. Caspase‑1 was decreased at the transcriptional level and the cleaved caspase‑1 was decreased at the protein level. Secretion of IL‑1β and IL‑18 into the culture medium by cells transfected with miR‑223 was lower than that by the control cells. In conclusion, the tumor suppressor role of miR‑223 was associated with the regulation of NLRP3 inflammasome components. miR‑223 inhibited HCC cell proliferation and promoted apoptosis by directly targeting NLRP3. Downstream production of caspase‑1, IL‑1β and IL‑18 were also repressed by miR‑223. These results provided insight into the association between the innate immune system and the genesis of HCC. [ABSTRACT FROM AUTHOR]