AIM: To explore the effect of miR-22 on viability, migration, invasion and apoptosis in retinoblastoma (RB) Y79 cells and to further detect the potential mechanism. METHODS: Plasmids were constructed to change the expression level of miR-22 in Y79 cells. Real-time reverse transcription polymerase chain reaction (RT-PCR) was conducted to test the expression level of miR-22. After changing the expression of miR-22, the mRNA and protein levels of high-mobility group box 1 (HMGB1) were investigated using RT-PCR and Western blotting. The effect of miR-22 on viability was analyzed by using cell counting kit-8 (CCK-8) assay and the effect on apoptosis was detected by the flow cytometry. Wound healing migration assay and Transwell invasion assay were used to detect the effects of miR-22 on cell motility. RESULTS: miR-22 inhibited viability, migration and invasion, while promoting apoptosis, in RB Y79 cells. The inhibition rate of miR-22 overexpression group at 12, 24, 48h was 11.71%±2.54%, 21.36%±1.39% and 29.44%±1.15%, respectively. Cellular apoptosis was higher in miR-22 overexpression group (17.00%±0.39%) compared with negative control (4.38%±0.38%). miR-22 negatively mediated the expression of HMGB1. Furthermore, decreased HMGB1 significantly attenuated viability, migration and invasion, while promoting apoptosis. Enforced expression of HMGB1 partially rescued the effects of miR-22 overexpression on cell viability, migration, invasion and apoptosis. Moreover, the phosphorylated protein kinase B (p-AKT) was significantly downregulated in the HMGB1 shRNA group and miR-22 overexpression group and elevated in the HMGB1 overexpression group compared with the normal control. CONCLUSION: miR-22 inhibites viability, migration and invasion and increases apoptosis in Y79 cells by targeting HMGB1. These findings may provide a therapeutic strategy for RB.