Errors in geography: In many exterior scenes, California hills are visible in the background. South Florida is mostly flat.
Factual errors: While often the science and technology portrayed in the series (as well as the other CSI series) is accurate or mirrors sound scientific principle, there have been times when methods have led to results simply not possible in the real world.
Errors made by characters (possibly deliberate errors by the filmmakers): Numerous times a character will refer to Miami University. Miami University is located in Oxford, Ohio; the University of Miami is located in Florida.
Factual errors: In the Czech dubbing of the series, the female character Maxine Valera is often referred to as a man, "Valera" being "his" first name. This is caused by the lack of knowledge of the translators in terms of first name/last name usage in the United States. In Czech, a name sounding similar to "Valera" would be men's name.