The Internet has quickly gained popularity as a major source of health-related information, but its impact is unclear. Here, we investigate the extent to which advocacy websites for three neurodevelopmental disorders—cerebral palsy (CP), autism spectrum disorder (ASD) and fetal alcohol spectrum disorder (FASD)—inform stakeholders about treatment options, and discuss the ethical challenges inherent in providing such information online. We identified major advocacy websites for each disorder and assessed website accountability, the number, attributes, and accessibility of treatments described, and the valence of treatment information. With the exception of FASD websites, we found that advocacy websites provide a plethora of information about a wide variety of readily available products and services. Treatment information is primarily targeted at families and is overwhelmingly encouraging, regardless of the type or conventionality of treatments. Many websites acknowledge corporate sponsors. While the majority do not overtly advertise or endorse specific brands, they also do not prominently display disclaimers about the nature and intent of treatment information. Thus, while advocacy websites are organized to serve as information clearinghouses, they implicitly appear to provide endorsement of selected treatments and services. We conclude with recommendations for new partnerships between government-funded health organizations, advocacy and investigators to make more transparent the role of online information in informing treatment options and improving the evaluation of information.