Exposure to endocrine disruptors (EDs) has been implicated in the rising incidence of hormone-related health problems in fish, wildlife and humans. As a result, regulatory policies have been established in other countries to minimize or prevent its release into the environment. The contamination of Laguna de Bay with the endocrine disrupting hormone 17beta-estradiol (E2) has been recently documented with both caged and feral male fish from the lake demonstrating a female characteristic (i.e. vitellogenin synthesis) and atypical features of the reproductive organ. There is a need to evaluate fish populations in threatened freshwater systems in the country such as the lesser-studied Seven Lakes of San Pablo for endocrine disruption, a significant issue in contemporary environmental science. Addressing the gaps in our understanding of the behavior of EDs in a tropical country like the Philippines will provide a better comprehension of its local health risks and will be of help in designing appropriate strategies to address its potential impacts.