Inflammation is now recognized as being pivotal in the pathogenesis of atherosclerosis. This review highlights key concepts in our current understanding of the role of inflammation in the initiation, progression, and complication of atherosclerosis. The role of various triggers and amplifiers and the innate and adaptive immunity in the cascade of inflammatory events are also presented. Progress in our understanding of the inflammatory pathways in atherosclerosis has provided further mechanistic insight into the clinical benefits of current medical therapy and may alter our future treatment and preventive strategies.