PD98059 is the specific inhibitor of extracellular signaling-regulated kinase (ERK) kinase (MEK). ERK is involved in a mitogen-activated protein kinase (MAPK) cascade controlling cell growth and differentiation. Although the inhibition of ERK is known to induce cell death in various cell lines, this effect is still controversial and the role of PD98059 on the death of HeLa $S_3$ cells, a subclone of the cervical cancer cell line, is not well understood. The apoptosis of HeLa $S_3$ cells increased after the treatment of 50 ${mu}M$ PD98059. The induction of apoptosis by PD98059 was occurred in a time- and a dose-dependent manners. The expression of Bcl-2 was reduced in accordance with decrease of ERK2 expression. Taken together, these results indicate that PD98059 has a cytotoxicity in HeLa $S_3$ cells and it may be used as a potential target for the treatment of cervical cancer.