Long non-coding RNAs (lncRNAs) play a crucial role in modulating cancer progression and metastasis. This study investigates the tumor-promoting function of long non-coding RNA BCAR4 in osteosarcoma and elucidates its regulatory mechanism. Although BCAR4 acts as a tumor promoter in osteosarcoma, its regulatory mechanism remains unclear. Bioinformatic analysis revealed a specific interaction between BCAR4 and miR-1260a, with osteosarcoma exhibiting elevated miR-1260a expression inversely correlated with BCAR4 expression. Overexpression of BCAR4 significantly suppressed miR-1260a expression, indicating regulation between BCAR4 and miR-1260a. Luciferase reporter assays confirmed a direct association between miR-1260a and BCAR4 at the sequence level. Silencing of BCAR4 inhibited osteosarcoma cell proliferation and migration while promoting cellular apoptosis, primarily mediated by miR-1260a. Our findings demonstrate that BCAR4 functions as a tumor promotor in osteosarcoma, and that its activity is regulated by miR-1260a. This study also proposes a potential therapeutic approach for treating osteosarcoma by targeting the BCAR4/miR-1260a axis. These different insights shed light on the intricate regulatory network underlying osteosarcoma pathogenesis and offer promising avenues for developing targeted therapies against this aggressive cancer.