As a component of the nuclear remodeling and deacetylation complex (NuRD complex), metastasis-associated gene 1 (MTA1) has been reported to play a key role in cancer malignancy. However, whether MTA1 functions in small cell lung cancer (SCLC) malignant behavior and whether it is feasible to be used as a therapeutic target have not been evaluated. The present study aimed to investigate the effects of MTA1 downregulation on SCLC malignancy. First we demonstrated the overexpression of MTA1 in SCLC specimens. After knocking down the MTA1 level by specific siRNA sequence, the biological consequences on proliferation, migration, invasion and apoptosis were evaluated. The results showed that MTA1 silencing had potent suppressive effects on SCLC proliferation, migration and invasion. Apoptosis but not cell cycle arrest was induced in the MTA1-silenced SCLC cells. In summary, MTA1 plays a critical role in regulating the malignant behaviors of SCLC. Depleting MTA1 level may be an effective strategy by which to suppress SCLC growth and metastasis in future biotherapeutic attempts.