On July 24, 2007, Dr Albert Ellis, one of the giants of clinical psychology, died at 93 years of age. He was recognized as one of the most important figures of contemporary psychology, to the point of being considered by his peers to be more influential than Sigmund Freud. In this article we gather some biographical data of Dr. Ellis and we pay an academic tribute remembering the foundations of his main contribution: Rational Emotive Behavior Therapy (REBT). His theory of emotional disturbance, a list of the main irrational beliefs, his intervention model denominated A-B-C-D-E, and a comparison with the cognitive therapy are included.