AIM: To investigate the effect of nobiletin (Nob) on cardiomyocyte hypertrophy induced by high glucose and its mechanism. METHODS: Neonatal rat cardiomyocytes (NRCMS) were stimulated with high glucose (HG) to establish cardiomyocyte hypertrophy and nobiletin was given. Cell viability was measured by MTT assay. C-myc and Nppa mRNA levels were detected by qRT-PCR. Cellular surface area was detected by immunofluorescence, and Nrf2 and HO-1 protein expressions were detected by Western blot. RESULTS: After stimulation with 33.3 mmol/L HG for 48 h, the survival rate of NRCMS was significantly decreased, C-myc, Nppa mRNA levels and cellular surface area were significantly increased, Nrf2 and HO-1 protein expression were significantly decreased (P<0.05). After Nob treatment, compared with HG group, cellular surface area, Nrf2 and HO-1 protein expression were significantly increased, C-myc and Nppa mRNA levels were significantly decreased. The above indexes were reversed by using Nrf2 inhibitor. CONCLUSION: Nob inhibits cardiomyocyte hypertrophy induced by high glucose, and its mechanism may be related to the activation of Nrf2/HO-1 signaling pathway.