Recent cohort and case-control studies have suggested that cigarette smoking may be involved in the etiology of leukemia. Rising trends have been observed for all leukemias when the amount of cigarettes smoked increased. However, the magnitude of the trend was strongest for myeloid leukemia. Although no detailed biological mechanism has been proposed, a causal link is made plausible by evidence of systemic effects of cigarette smoke and the presence in cigarette smoke of chemicals (benzene) and radioactive substances that have been associated with leukemia risk. Cigarette smoking has a deleterious effect on survival in leukemia by shortening complete remission duration and subsequent survival. The data reported in this review are derived from the medical literature and from the experience of the authors.