"The terrorist attack on Theo van Gogh has unleashed feelings of great fear and insecurity in society," presiding Judge Udo Willem Bentinck said in his ruling.
Van Gogh, who was known as a fierce critic of Islam and multicultural society, was shot and stabbed in broad daylight in November 2004 by Mohammed
Bouyeri, a Dutch man of Moroccan descent.
During the trial two weeks ago, Bouyeri insisted the law obligated him to chop off the head of anyone who insults Allah and the prophet and requested a maximum sentence.
Van Gogh, a distant relative of the painter Vincent van Gogh, had made a short film in cooperation with a Somali-Dutch woman, in which Islam was linked to the abuse of women.