Emerging evidence has found that microRNAs (miRNA) play an important role in breast cancer. MiR-548 family has been demonstrated to be involved in the pathogenesis of several cancers. However, its role in breast cancer has not yet been elucidated. To explore this concern, we explored the expression of miR-548-3p in clinical specimens and breast cancer cells by qRT-PCR. In addition, an CCK-8 assay and Caspase 3/7 activity were used to evaluated the rates of cell proliferation and apoptosis. Protein expression was analyzed by western blotting and the target gene was confirmed using a luciferase reporter assay. Our results illustrated that miR-548-3p was significantly downregulated in breast cancer. Overexpression of miR-548-3p inhibited the proliferation and promoted the apoptosis of breast cancer cells. In addition, ECHS1 expression was demonstrated to be significantly upregulated in breast cancer tissues and cells, and the ECHS1 gene was identified to be one target of miR-548-3p. Therefore, our results demonstrated that miR-548-3p inhibited the proliferation of breast cancer cells by regulating the expression of ECHS1, indicating its potential as a therapeutic target for breast cancer.