In the present work, we have analyzed the effect of the essential fatty acid, alpha linolenic acid (ALA) on nitric oxide release as well as induction of lipid peroxidation in breast (MCF-7 and MDA-MB-231) and cervical (SiHa and HeLa) cancer cell lines. ALA-treated cells showed a dose-dependent decrease in cell viability in both breast and cervical cancer cell lines without affecting the viability of non-cancerous transformed HEK 293 cells. Both types of cancer cells treated with ALA demonstrated a significant reduction in nitric oxide (NO) release with a simultaneous increase in lipid peroxidation (LPO). This was followed by a decrease in the mitochondrial membrane potential as well as activation of caspase 3 leading to apoptosis. Thus, ALA regulated the growth of cancer cell lines through induction of lipid peroxidation and modulation of nitric oxide release resulting in apoptosis.