miR-1284 has been reported to inhibit tumor growth in some human cancers, including lung cancer, ovarian cancer, and gastric cancer. Whether it regulates breast cancer progression remains elusive. In this study, we found that miR-1284 was downregulated in breast cancer tissues and cell lines compared to normal control cells. Moreover, we showed that overexpression of miR-1284 significantly inhibited the proliferation, migration, and invasion of breast cancer cells while promoting apoptosis. In terms of mechanism, we found that transcription factor ZIC2 was a target of miR-1284 in breast cancer cells. Through the luciferase reporter assay, we demonstrated their direct interaction. RT-qPCR and Western blot also indicated that miR-1284 overexpression inhibited the protein levels of ZIC2 in breast cancer cells. Moreover, we found that ZIC2 knockdown inhibited the proliferation, migration, and invasion of breast cancer cells, whereas restoration of ZIC2 reversed the effects of miR-1284 on breast cancer cells. Taken together, our findings demonstrated that miR-1284 suppressed the proliferation, migration, and invasion of breast cancer cells via targeting ZIC2, which provided a new insight on the development of therapeutic targets for breast cancer treatment.