The protest was peaceful, but 30 police officers stood by to maintain order in case of any disorder.
The protesters denounced those who took part in the production of the film, "Innocence of Muslims," demanding that the United States punish the film producer and those involved.
They also submitted a letter via the consulate official to US ambassador Kristie Kenney who is scheduled to attend a seminar later today at Chiang Mai University.
Freedom of speech, and of the media, is considered a basic freedom in the United States. In its system of government the authorities do not have the right to limit the freedom of speech.
At the university seminar this afternoon, Ambassador Kenney is expected to explain applications of freedom of speech in her country.