Phosphatidylcholine is one of major phospholipid comprising cellular membrane and has been known to have several health-promoting activities, including improvement of brain function and liver repair. In the present, we examined the in vivo effect of dietary supplementation with phosphatidylcholine on response to environmental stressors and aging in C. elegans. Treatment with phosphatidylcholine significantly increased survival of worms under oxidative stress conditions. However, there was no significant difference in response to stresses caused by heat shock or ultraviolet irradiation. Oxidative stress is believed to be one of major causal factors of aging. Then, we examined the effect of phosphatidylcholine on lifespan and age-related physiological changes. Phosphatidylcholine showed a lifespan-extending effect and a reduction in fertility, possibly as a trade-off for a long lifespan. Age-related decline of motility was also significantly delayed by the supplementation with phosphatidylcholine. Interestingly, the expressions of well-known lifespan-extension-assuring genes, hsp-16.2 and sod-3, was significantly up-regulated by dietary intervention with phosphatidylcholine. Phosphatidylcholine also induced nuclear localization of DAF-16, a transcription factor modulating expression of genes involved in stress response and aging. Supplementation with phosphatidylcholine suppressed amyloid beta-induced toxicity in Alzheimer’s disease model animals. Our data showed anti-oxidant and anti-aging activities of phosphatidylcholine for the first time in vivo. Further studies focusing on the identification of underlying cellular mechanisms involved in the anti-aging effect will increase the possibility of using phosphatidylcholine for the development of anti-aging therapeutics.