Critics of Generation Rescue point out that the vast majority of the science that Generation Rescue base their case on that it is either not [[Peer review|peer reviewed]] or fails to establish a causative connection between thimerosal/vaccines and autism or both. In particular, the 'landmark' article that Generation Rescue rely on [http://www.attorneyaccess.net/documents/Bernard-Autism-ANovelFormofMercuryPoisoning.pdf Autism: A Novel Form of Mercury Poisoning] has been [http://pediatrics.aappublications.org/cgi/content/full/111/3/674 refuted]. There is no reason to think that autism did not exist before 1931 as JB Handley strongly asserts.{{fact}}
JB Handley claims that autism symptoms can be reversed. Autism is a neurological condition, if, as Generation Rescue broadly claim, autism signs can be reversed using chelation, this is in contradiction of the scientific capabilities of chelation. Quote from [http://www.healthofchildren.com/G-H/Heavy-Metal-Poisoning.html Encyclopedia of Children's Health] "Prognosis - The chelation process can only halt further effects of the poisoning; it cannot reverse neurological damage already sustained." Therefore any effects from mercury poisoning that appeared to simulate autism would not be reversed by such treatment anyway.
Also, the second ''[[New York Times]]'' advertisement (see above) had to undergo several alterations due to at least six of the scientists and researchers, who were thanked by name in the ad, wanting to [http://autismdiva.blogspot.com/2005/11/general-confusion-and-nyt.html disassociate their work] from the mercury/autism connection. This group of scientists wrote: "we believe GenerationRescue’s advertisement, at first appearance an innocuous gesture of appreciation, may actually mislead the public into thinking that the mercury-autism hypothesis has stronger support in the scientific literature than it actually does." One of the scientists who signed that letter asking not to be associated with the mercury/autism hypothesis, Martha Herbert, is still frequently cited by Generation Rescue and others as a supporter.
Many have also expressed concern of the allegedly heavy handed behaviors exhibited by Generation Rescue's leadership and some of its Rescue Angels. These include alleged [http://www.neurodiversity.com/rescue_angels.html verbal bullying of autistics], the making of accusations of [http://www.kevinleitch.co.uk/wp/?p=299 child abuse aimed at all parents of autistics who do not chelate their children] and [http://adventuresinautism.blogspot.com/2005/11/orac-gets-punked.html buying up of domains] with names similar to those websites in opposition to Generation Rescue and directing them to the Generation Rescue site.
Generation Rescue's home page has been criticized for containing inaccuracies regarding the prevalence of autism. As of 2006, it claimed that the prevalence of autism in the 1970s was 1 in 10,000 (in a paragraph that has been subsequently removed). In reality, the prevalence of autism was known to be 4-5 in 10,000 in the 1960s. Handley has been asked to cite the lower prevalence number, but has not come forward with a reply. Additionally, the site does not clarify that the prevalence of 1 in 166 is for ASD, not Kanner autism as is the lower prevalence number. The increase of 6000% (60 times) claimed in the GR home page should be about 1200% (12 times) if the lower prevalence number is corrected. This type of prevalence change claim has been characterized as a comparison of "oranges with sheep" [http://www.foxnews.com/story/0,2933,162314,00.html].
