Poster and write-up presented at the 2019 annual American Association for the Advancement of Science The objective of this study was to understand the effects of acetaminophen on Caenorhabditis elegans lifespan and fertility. The experiment was based off a study that assessed the effect of aspirin on the lifespan of C. elegans. The original study showed that aspirin causes stress in C. elegans similar to caloric restriction, resulting in increased stress resilience and prolonged longevity. Assuming that acetaminophen treatment invokes a similar mechanism, the expectation was to observe prolonged lifespan and decreased egg production, one of the known stress outcomes in C. elegans. Wildtype and daf-9 mutant C. elegans were provided with OP50 Escherichia coli seeded plates containing a diluted concentration of acetaminophen and water at 50, 100, and 200mM, each plate hosting 4 worms of the same type. The plates were assigned to 5 study groups: 3 treatment groups corresponding to each treatment concentration had 3 wildtype C. elegans plates each, 2 plates with untreated wildtype C. elegans were assigned as a control group, and 2 plates with daf-9 treatment group with 100mM acetaminophen concentration. Daf-9 mutants were included as they have been shown to be stress resistant compared to wildtype worms. The observed increased movement speed suggests that acetaminophen solution causes stress in C. elegans worms. Increased egg production in the wildtype C. elegans treatment groups was also observed when compared to the control groups. The highest average egg laying per worm was observed in the lowest concentration of acetaminophen treatment group and declined as the concentration of acetaminophen increased. The results of this study showed that treating C. elegans with acetaminophen increased both their egg laying (at low concentrations) and lifespan (at higher concentrations), similar to the findings of the aspirin study. Conducting the experiment only once and therefore needing to verify reproducibility and statistical significance of the results is the main limitation of the study.