The worldwide spread of tobacco use in recent decades raises questions about the relative prevalence of smoking among men and women. Does the degree of gender equality in nations promote equality in cigarette use? Does rising use of cigarettes by women stem from the stage of cigarette diffusion and earlier increases among men? Or have changes in economic factors and smoking policy affected the sexes differently? This study uses aggregate data for 106 nations, measures of smoking prevalence circa 2000, and lagged measures of gender equality, cigarette diffusion, and tobacco access to address these questions and evaluate the underlying theories. With the logged ratio of female to male prevalence as the dependent variable, regression results reveal that gender equality has inconsistent effects on women's smoking relative to men, cigarette diffusion has more consistent and moderately strong effects, and economic factors have weak effects. Global patterns of adoption of cigarettes by women appear most closely associated with the early adoption by men and then movement through a regular pattern of cigarette diffusion.