Nelson Mandela spent how many years in prison? 26/04/201216/12/2016 WhereWhyWhen.com Nelson Mandela spent 27 years in prison, and was released in 1990. Video: A clip with Nelson Mandela not long after he had been released. Did you enjoy this post? Share your comments below. Review Product / Answer Submit your reviewRating: 12345 Review: Check this box to confirm you are human.