In the honey bee (Apis mellifera), depending on what they are fed, female eggs become either workers or queens. Although queens and workers share a common genome, the maximum lifespan of queens is an order-of-magnitude longer than workers. The mechanistic basis of this longevity difference is unknown. In order to test if differences in membrane composition could be involved we have compared the fatty acid composition of phospholipids of queen and worker honey bees. The cell membranes of both young and old honey bee queens are highly monounsaturated with very low content of polyunsaturates. Newly emerged workers have a similar membrane fatty acid composition to queens but within the first week of hive life, they increase the polyunsaturate content and decrease the monounsaturate content of their membranes, probably as a result of pollen consumption. This means their membranes likely become more susceptible to lipid peroxidation in this first week of hive life. The results support the suggestion that membrane composition might be an important factor in the determination of maximum lifespan. Assuming the same slope of the relationship between membrane peroxidation index and maximum lifespan as previously observed for mammal and bird species, we propose that the 3-fold difference in peroxidation index of phospholipids of queens and workers is large enough to account for the order-of-magnitude difference in their longevity.